Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

72 files changed, 15606 insertions, 0 deletions

diff --git a/tools/profiler/tests/browser/browser.ini b/tools/profiler/tests/browser/browser.ini
new file mode 100644
index 0000000000..9a02b673d2
--- /dev/null
+++ b/tools/profiler/tests/browser/browser.ini
@@ -0,0 +1,102 @@
+[DEFAULT]
+skip-if = tsan # Bug 1804081 - TSan times out on pretty much all of these tests
+support-files =
+  ../shared-head.js
+  head.js
+
+[browser_test_feature_ipcmessages.js]
+support-files = simple.html
+
+[browser_test_feature_jsallocations.js]
+support-files = do_work_500ms.html
+
+[browser_test_feature_nostacksampling.js]
+support-files = do_work_500ms.html
+
+[browser_test_feature_preferencereads.js]
+support-files = single_frame.html
+
+[browser_test_markers_parent_process.js]
+skip-if =
+  os == "win" && os_version == "6.1" # Skip on Azure - frequent failure
+
+[browser_test_markers_gc_cc.js]
+
+[browser_test_profile_capture_by_pid.js]
+skip-if = os == "win" && os_version == "6.1" # No thread names on win7, needed for these tests
+https_first_disabled = true
+support-files = single_frame.html
+
+[browser_test_profile_fission.js]
+support-files = single_frame.html
+
+[browser_test_profile_single_frame_page_info.js]
+https_first_disabled = true
+support-files = single_frame.html
+
+[browser_test_profile_slow_capture.js]
+https_first_disabled = true
+support-files = single_frame.html
+skip-if = !debug
+
+[browser_test_profile_multi_frame_page_info.js]
+https_first_disabled = true
+support-files =
+  multi_frame.html
+  single_frame.html
+
+[browser_test_marker_network_simple.js]
+https_first_disabled = true
+support-files = simple.html
+
+[browser_test_marker_network_private_browsing.js]
+support-files = simple.html
+
+[browser_test_marker_network_cancel.js]
+https_first_disabled = true
+support-files = simple.html
+
+[browser_test_marker_network_sts.js]
+support-files = simple.html
+
+[browser_test_marker_network_redirect.js]
+https_first_disabled = true
+support-files =
+  redirect.sjs
+  simple.html
+  page_with_resources.html
+  firefox-logo-nightly.svg
+skip-if =
+  os == "win" && os_version == "6.1" # Skip on Azure - frequent failure
+
+[browser_test_marker_network_serviceworker_cache_first.js]
+support-files =
+  serviceworkers/serviceworker-utils.js
+  serviceworkers/serviceworker_register.html
+  serviceworkers/serviceworker_page.html
+  serviceworkers/firefox-logo-nightly.svg
+  serviceworkers/serviceworker_cache_first.js
+
+[browser_test_marker_network_serviceworker_no_fetch_handler.js]
+support-files =
+  serviceworkers/serviceworker-utils.js
+  serviceworkers/serviceworker_register.html
+  serviceworkers/serviceworker_page.html
+  serviceworkers/firefox-logo-nightly.svg
+  serviceworkers/serviceworker_no_fetch_handler.js
+
+[browser_test_marker_network_serviceworker_no_respondWith_in_fetch_handler.js]
+support-files =
+  serviceworkers/serviceworker-utils.js
+  serviceworkers/serviceworker_register.html
+  serviceworkers/serviceworker_page.html
+  serviceworkers/firefox-logo-nightly.svg
+  serviceworkers/serviceworker_no_respondWith_in_fetch_handler.js
+
+[browser_test_marker_network_serviceworker_synthetized_response.js]
+support-files =
+  serviceworkers/serviceworker-utils.js
+  serviceworkers/serviceworker_register.html
+  serviceworkers/serviceworker_simple.html
+  serviceworkers/firefox-logo-nightly.svg
+  serviceworkers/serviceworker_synthetized_response.js
diff --git a/tools/profiler/tests/browser/browser_test_feature_ipcmessages.js b/tools/profiler/tests/browser/browser_test_feature_ipcmessages.js
new file mode 100644
index 0000000000..4691be6434
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_feature_ipcmessages.js
@@ -0,0 +1,109 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+requestLongerTimeout(10);
+
+async function waitForLoad() {
+  return SpecialPowers.spawn(gBrowser.selectedBrowser, [], () => {
+    return new Promise(function(resolve) {
+      if (content.document.readyState !== "complete") {
+        content.document.addEventListener("readystatechange", () => {
+          if (content.document.readyState === "complete") {
+            resolve();
+          }
+        });
+      } else {
+        resolve();
+      }
+    });
+  });
+}
+
+/**
+ * Test the IPCMessages feature.
+ */
+add_task(async function test_profile_feature_ipcmessges() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  const url = BASE_URL + "simple.html";
+
+  info("Open a tab while profiling IPC messages.");
+  await startProfiler({ features: ["js", "ipcmessages"] });
+  info("Started the profiler sucessfully! Now, let's open a tab.");
+
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    info("We opened a tab!");
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+    info("Now let's wait until it's fully loaded.");
+    await waitForLoad();
+
+    info(
+      "Check that some IPC profile markers were generated when " +
+        "the feature is enabled."
+    );
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await waitSamplingAndStopProfilerAndGetThreads(contentPid);
+
+      Assert.greater(
+        getPayloadsOfType(parentThread, "IPC").length,
+        0,
+        "IPC profile markers were recorded for the parent process' main " +
+          "thread when the IPCMessages feature was turned on."
+      );
+
+      Assert.greater(
+        getPayloadsOfType(contentThread, "IPC").length,
+        0,
+        "IPC profile markers were recorded for the content process' main " +
+          "thread when the IPCMessages feature was turned on."
+      );
+    }
+  });
+
+  info("Now open a tab without profiling IPC messages.");
+  await startProfiler({ features: ["js"] });
+
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+    await waitForLoad();
+
+    info(
+      "Check that no IPC profile markers were recorded when the " +
+        "feature is turned off."
+    );
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await waitSamplingAndStopProfilerAndGetThreads(contentPid);
+      Assert.equal(
+        getPayloadsOfType(parentThread, "IPC").length,
+        0,
+        "No IPC profile markers were recorded for the parent process' main " +
+          "thread when the IPCMessages feature was turned off."
+      );
+
+      Assert.equal(
+        getPayloadsOfType(contentThread, "IPC").length,
+        0,
+        "No IPC profile markers were recorded for the content process' main " +
+          "thread when the IPCMessages feature was turned off."
+      );
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_feature_jsallocations.js b/tools/profiler/tests/browser/browser_test_feature_jsallocations.js
new file mode 100644
index 0000000000..0ae3b53a14
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_feature_jsallocations.js
@@ -0,0 +1,78 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+requestLongerTimeout(10);
+
+/**
+ * Test the JS Allocations feature. This is done as a browser test to ensure that
+ * we realistically try out how the JS allocations are running. This ensures that
+ * we are collecting allocations for the content process and the parent process.
+ */
+add_task(async function test_profile_feature_jsallocations() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  await startProfiler({ features: ["js", "jsallocations"] });
+
+  const url = BASE_URL + "do_work_500ms.html";
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    // Wait 500ms so that the tab finishes executing.
+    await wait(500);
+
+    // Check that we can get some allocations when the feature is turned on.
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await waitSamplingAndStopProfilerAndGetThreads(contentPid);
+      Assert.greater(
+        getPayloadsOfType(parentThread, "JS allocation").length,
+        0,
+        "Allocations were recorded for the parent process' main thread when the " +
+          "JS Allocation feature was turned on."
+      );
+      Assert.greater(
+        getPayloadsOfType(contentThread, "JS allocation").length,
+        0,
+        "Allocations were recorded for the content process' main thread when the " +
+          "JS Allocation feature was turned on."
+      );
+    }
+
+    await startProfiler({ features: ["js"] });
+    // Now reload the tab with a clean run.
+    gBrowser.reload();
+    await wait(500);
+
+    // Check that no allocations were recorded, and allocation tracking was correctly
+    // turned off.
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await waitSamplingAndStopProfilerAndGetThreads(contentPid);
+      Assert.equal(
+        getPayloadsOfType(parentThread, "JS allocation").length,
+        0,
+        "No allocations were recorded for the parent processes' main thread when " +
+          "JS allocation was not turned on."
+      );
+
+      Assert.equal(
+        getPayloadsOfType(contentThread, "JS allocation").length,
+        0,
+        "No allocations were recorded for the content processes' main thread when " +
+          "JS allocation was not turned on."
+      );
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_feature_nostacksampling.js b/tools/profiler/tests/browser/browser_test_feature_nostacksampling.js
new file mode 100644
index 0000000000..695e6031aa
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_feature_nostacksampling.js
@@ -0,0 +1,76 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test the No Stack Sampling feature.
+ */
+add_task(async function test_profile_feature_nostacksampling() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  await startProfiler({ features: ["js", "nostacksampling"] });
+
+  const url = BASE_URL + "do_work_500ms.html";
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    // Wait 500ms so that the tab finishes executing.
+    await wait(500);
+
+    // Check that we can get no stacks when the feature is turned on.
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await stopProfilerNowAndGetThreads(contentPid);
+      Assert.equal(
+        parentThread.samples.data.length,
+        0,
+        "Stack samples were recorded from the parent process' main thread" +
+          "when the No Stack Sampling feature was turned on."
+      );
+      Assert.equal(
+        contentThread.samples.data.length,
+        0,
+        "Stack samples were recorded from the content process' main thread" +
+          "when the No Stack Sampling feature was turned on."
+      );
+    }
+
+    // Flush out any straggling allocation markers that may have not been collected
+    // yet by starting and stopping the profiler once.
+    await startProfiler({ features: ["js"] });
+
+    // Now reload the tab with a clean run.
+    gBrowser.reload();
+    await wait(500);
+
+    // Check that stack samples were recorded.
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await waitSamplingAndStopProfilerAndGetThreads(contentPid);
+      Assert.greater(
+        parentThread.samples.data.length,
+        0,
+        "No Stack samples were recorded from the parent process' main thread" +
+          "when the No Stack Sampling feature was not turned on."
+      );
+
+      Assert.greater(
+        contentThread.samples.data.length,
+        0,
+        "No Stack samples were recorded from the content process' main thread" +
+          "when the No Stack Sampling feature was not turned on."
+      );
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_feature_preferencereads.js b/tools/profiler/tests/browser/browser_test_feature_preferencereads.js
new file mode 100644
index 0000000000..d0f16054d8
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_feature_preferencereads.js
@@ -0,0 +1,116 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+requestLongerTimeout(10);
+
+const kContentPref = "font.size.variable.x-western";
+
+function countPrefReadsInThread(pref, thread) {
+  let count = 0;
+  for (let payload of getPayloadsOfType(thread, "PreferenceRead")) {
+    if (payload.prefName === pref) {
+      count++;
+    }
+  }
+  return count;
+}
+
+async function waitForPaintAfterLoad() {
+  return SpecialPowers.spawn(gBrowser.selectedBrowser, [], () => {
+    return new Promise(function(resolve) {
+      function listener() {
+        if (content.document.readyState == "complete") {
+          content.requestAnimationFrame(() => content.setTimeout(resolve, 0));
+        }
+      }
+      if (content.document.readyState != "complete") {
+        content.document.addEventListener("readystatechange", listener);
+      } else {
+        listener();
+      }
+    });
+  });
+}
+
+/**
+ * Test the PreferenceRead feature.
+ */
+add_task(async function test_profile_feature_preferencereads() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  await startProfiler({ features: ["js", "preferencereads"] });
+
+  const url = BASE_URL + "single_frame.html";
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    await waitForPaintAfterLoad();
+
+    // Ensure we read a pref in the content process.
+    await SpecialPowers.spawn(contentBrowser, [kContentPref], pref => {
+      Services.prefs.getIntPref(pref);
+    });
+
+    // Check that some PreferenceRead profile markers were generated when the
+    // feature is enabled.
+    {
+      const { contentThread } = await stopProfilerNowAndGetThreads(contentPid);
+
+      Assert.greater(
+        countPrefReadsInThread(kContentPref, contentThread),
+        0,
+        `PreferenceRead profile markers for ${kContentPref} were recorded ` +
+          "when the PreferenceRead feature was turned on."
+      );
+    }
+
+    await startProfiler({ features: ["js"] });
+    // Now reload the tab with a clean run.
+    await ContentTask.spawn(contentBrowser, null, () => {
+      return new Promise(resolve => {
+        addEventListener("pageshow", () => resolve(), {
+          capturing: true,
+          once: true,
+        });
+        content.location.reload();
+      });
+    });
+
+    await waitForPaintAfterLoad();
+
+    // Ensure we read a pref in the content process.
+    await SpecialPowers.spawn(contentBrowser, [kContentPref], pref => {
+      Services.prefs.getIntPref(pref);
+    });
+
+    // Check that no PreferenceRead markers were recorded when the feature
+    // is turned off.
+    {
+      const {
+        parentThread,
+        contentThread,
+      } = await stopProfilerNowAndGetThreads(contentPid);
+      Assert.equal(
+        getPayloadsOfType(parentThread, "PreferenceRead").length,
+        0,
+        "No PreferenceRead profile were recorded " +
+          "when the PreferenceRead feature was turned off."
+      );
+
+      Assert.equal(
+        getPayloadsOfType(contentThread, "PreferenceRead").length,
+        0,
+        "No PreferenceRead profile were recorded " +
+          "when the PreferenceRead feature was turned off."
+      );
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_cancel.js b/tools/profiler/tests/browser/browser_test_marker_network_cancel.js
new file mode 100644
index 0000000000..ee7f1ef3ca
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_cancel.js
@@ -0,0 +1,71 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers with the cancel status.
+ */
+add_task(async function test_network_markers_early_cancel() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = BASE_URL + "simple.html?cacheBust=" + Math.random();
+  const options = {
+    gBrowser,
+    url: "about:blank",
+    waitForLoad: false,
+  };
+
+  const tab = await BrowserTestUtils.openNewForegroundTab(options);
+  const loadPromise = BrowserTestUtils.waitForDocLoadAndStopIt(url, tab);
+  BrowserTestUtils.loadURI(tab.linkedBrowser, url);
+  const contentPid = await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [],
+    () => Services.appinfo.processID
+  );
+  await loadPromise;
+  const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+    contentPid
+  );
+  BrowserTestUtils.removeTab(tab);
+
+  const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+  const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+
+  info("parent process: " + JSON.stringify(parentNetworkMarkers, null, 2));
+  info("content process: " + JSON.stringify(contentNetworkMarkers, null, 2));
+
+  Assert.equal(
+    parentNetworkMarkers.length,
+    2,
+    `We should get a pair of network markers in the parent thread.`
+  );
+
+  // We don't test the markers in the content process, because depending on some
+  // timing we can have 0 or 1 (and maybe even 2 (?)).
+
+  const parentStopMarker = parentNetworkMarkers[1];
+
+  const expectedProperties = {
+    name: Expect.stringMatches(`Load \\d+:.*${escapeStringRegexp(url)}`),
+    data: Expect.objectContainsOnly({
+      type: "Network",
+      status: "STATUS_CANCEL",
+      URI: url,
+      requestMethod: "GET",
+      contentType: null,
+      startTime: Expect.number(),
+      endTime: Expect.number(),
+      id: Expect.number(),
+      pri: Expect.number(),
+      cache: "Unresolved",
+    }),
+  };
+
+  Assert.objectContains(parentStopMarker, expectedProperties);
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_private_browsing.js b/tools/profiler/tests/browser/browser_test_marker_network_private_browsing.js
new file mode 100644
index 0000000000..0a10ea7157
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_private_browsing.js
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly
+ */
+add_task(async function test_network_markers() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const win = await BrowserTestUtils.openNewBrowserWindow({
+    private: true,
+    fission: true,
+  });
+  try {
+    const url = BASE_URL_HTTPS + "simple.html?cacheBust=" + Math.random();
+    const contentBrowser = win.gBrowser.selectedBrowser;
+    BrowserTestUtils.loadURI(contentBrowser, url);
+    await BrowserTestUtils.browserLoaded(contentBrowser, false, url);
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    info(JSON.stringify(parentNetworkMarkers, null, 2));
+    info(JSON.stringify(contentNetworkMarkers, null, 2));
+
+    Assert.equal(
+      parentNetworkMarkers.length,
+      2,
+      `We should get a pair of network markers in the parent thread.`
+    );
+    Assert.equal(
+      contentNetworkMarkers.length,
+      2,
+      `We should get a pair of network markers in the content thread.`
+    );
+
+    const parentStopMarker = parentNetworkMarkers[1];
+    const contentStopMarker = contentNetworkMarkers[1];
+
+    const expectedProperties = {
+      name: Expect.stringMatches(`Load \\d+:.*${escapeStringRegexp(url)}`),
+      data: Expect.objectContains({
+        status: "STATUS_STOP",
+        URI: url,
+        requestMethod: "GET",
+        contentType: "text/html",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+        id: Expect.number(),
+        count: Expect.number(),
+        pri: Expect.number(),
+        isPrivateBrowsing: true,
+      }),
+    };
+
+    Assert.objectContains(parentStopMarker, expectedProperties);
+    // The cache information is missing from the content marker, it's only part
+    // of the parent marker. See Bug 1544821.
+    Assert.objectContains(parentStopMarker.data, {
+      // Because the request races with the cache, these 2 values are valid:
+      // "Missed" when the cache answered before we get a result from the network.
+      // "Unresolved" when we got a response from the network before the cache subsystem.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+    Assert.objectContains(contentStopMarker, expectedProperties);
+  } finally {
+    await BrowserTestUtils.closeWindow(win);
+  }
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_redirect.js b/tools/profiler/tests/browser/browser_test_marker_network_redirect.js
new file mode 100644
index 0000000000..28478c2b3b
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_redirect.js
@@ -0,0 +1,341 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test the redirect cases.
+ */
+add_task(async function test_network_markers_service_worker_setup() {
+  // Disabling cache makes the result more predictable especially in verify mode.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_redirect_simple() {
+  // In this test, we request an HTML page that gets redirected. This is a
+  // top-level navigation.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const targetFileNameWithCacheBust = "simple.html";
+  const url =
+    BASE_URL +
+    "redirect.sjs?" +
+    encodeURIComponent(targetFileNameWithCacheBust);
+  const targetUrl = BASE_URL + targetFileNameWithCacheBust;
+
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    info(JSON.stringify(parentNetworkMarkers, null, 2));
+    info(JSON.stringify(contentNetworkMarkers, null, 2));
+
+    Assert.equal(
+      parentNetworkMarkers.length,
+      4,
+      `We should get 2 pairs of network markers in the parent thread.`
+    );
+
+    /* It looks like that for a redirection for the top level navigation, the
+     * content thread sees the markers for the second request only.
+     * See Bug 1692879. */
+    Assert.equal(
+      contentNetworkMarkers.length,
+      2,
+      `We should get one pair of network markers in the content thread.`
+    );
+
+    const parentRedirectMarker = parentNetworkMarkers[1];
+    const parentStopMarker = parentNetworkMarkers[3];
+    // There's no content redirect marker for the reason outlined above.
+    const contentStopMarker = contentNetworkMarkers[1];
+
+    Assert.objectContains(parentRedirectMarker, {
+      name: Expect.stringMatches(`Load \\d+:.*${escapeStringRegexp(url)}`),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_REDIRECT",
+        URI: url,
+        RedirectURI: targetUrl,
+        requestMethod: "GET",
+        contentType: null,
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+        id: Expect.number(),
+        redirectId: parentStopMarker.data.id,
+        pri: Expect.number(),
+        cache: Expect.stringMatches(/Missed|Unresolved/),
+        redirectType: "Permanent",
+        isHttpToHttpsRedirect: false,
+      }),
+    });
+
+    const expectedProperties = {
+      name: Expect.stringMatches(
+        `Load \\d+:.*${escapeStringRegexp(targetUrl)}`
+      ),
+    };
+    const expectedDataProperties = {
+      type: "Network",
+      status: "STATUS_STOP",
+      URI: targetUrl,
+      requestMethod: "GET",
+      contentType: "text/html",
+      startTime: Expect.number(),
+      endTime: Expect.number(),
+      domainLookupStart: Expect.number(),
+      domainLookupEnd: Expect.number(),
+      connectStart: Expect.number(),
+      tcpConnectEnd: Expect.number(),
+      connectEnd: Expect.number(),
+      requestStart: Expect.number(),
+      responseStart: Expect.number(),
+      responseEnd: Expect.number(),
+      id: Expect.number(),
+      count: Expect.number(),
+      pri: Expect.number(),
+    };
+
+    Assert.objectContains(parentStopMarker, expectedProperties);
+    Assert.objectContains(contentStopMarker, expectedProperties);
+
+    // The cache information is missing from the content marker, it's only part
+    // of the parent marker. See Bug 1544821.
+    Assert.objectContainsOnly(parentStopMarker.data, {
+      ...expectedDataProperties,
+      // Because the request races with the cache, these 2 values are valid:
+      // "Missed" when the cache answered before we get a result from the network.
+      // "Unresolved" when we got a response from the network before the cache subsystem.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+    Assert.objectContainsOnly(contentStopMarker.data, expectedDataProperties);
+  });
+});
+
+add_task(async function test_network_markers_redirect_resources() {
+  // In this test we request an HTML file that itself contains resources that
+  // are redirected.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = BASE_URL + "page_with_resources.html?cacheBust=" + Math.random();
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    info(JSON.stringify(parentNetworkMarkers, null, 2));
+    info(JSON.stringify(contentNetworkMarkers, null, 2));
+
+    Assert.equal(
+      parentNetworkMarkers.length,
+      8,
+      `We should get 4 pairs of network markers in the parent thread.`
+      // 1 - The main page
+      // 2 - The SVG
+      // 3 - The redirected request for the second SVG request.
+      // 4 - The SVG, again
+    );
+
+    /* In this second test, the top level navigation request isn't redirected.
+     * Contrary to Bug 1692879 we get all network markers for redirected
+     * resources. */
+    Assert.equal(
+      contentNetworkMarkers.length,
+      8,
+      `We should get 4 pairs of network markers in the content thread.`
+    );
+
+    // The same resource firefox-logo-nightly.svg is requested twice, but the
+    // second time it is redirected.
+    // We're not interested in the main page, as we test that in other files.
+    // In this page we're only interested in the marker for requested resources.
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+
+    const parentFirstStopMarker = parentPairs[1][1];
+    const parentRedirectMarker = parentPairs[2][1];
+    const parentSecondStopMarker = parentPairs[3][1];
+    const contentFirstStopMarker = contentPairs[1][1];
+    const contentRedirectMarker = contentPairs[2][1];
+    const contentSecondStopMarker = contentPairs[3][1];
+
+    const expectedCommonDataProperties = {
+      type: "Network",
+      requestMethod: "GET",
+      startTime: Expect.number(),
+      endTime: Expect.number(),
+      id: Expect.number(),
+      pri: Expect.number(),
+      innerWindowID: Expect.number(),
+    };
+
+    // These properties are present when a connection is fully opened. This is
+    // most often the case, unless we're in verify mode, because in that case
+    // we run the same tests several times in the same Firefox and they might be
+    // cached, or in chaos mode Firefox may make all requests sequentially on
+    // the same connection.
+    // In these cases, these properties won't always be present.
+    const expectedConnectionProperties = {
+      domainLookupStart: Expect.number(),
+      domainLookupEnd: Expect.number(),
+      connectStart: Expect.number(),
+      tcpConnectEnd: Expect.number(),
+      connectEnd: Expect.number(),
+      requestStart: Expect.number(),
+      responseStart: Expect.number(),
+      responseEnd: Expect.number(),
+    };
+
+    const expectedPropertiesForStopMarker = {
+      name: Expect.stringMatches(/Load \d+:.*\/firefox-logo-nightly\.svg/),
+    };
+
+    const expectedDataPropertiesForStopMarker = {
+      ...expectedCommonDataProperties,
+      ...expectedConnectionProperties,
+      status: "STATUS_STOP",
+      URI: Expect.stringContains("/firefox-logo-nightly.svg"),
+      contentType: "image/svg+xml",
+      count: Expect.number(),
+    };
+
+    const expectedPropertiesForRedirectMarker = {
+      name: Expect.stringMatches(
+        /Load \d+:.*\/redirect.sjs\?firefox-logo-nightly\.svg/
+      ),
+    };
+
+    const expectedDataPropertiesForRedirectMarker = {
+      ...expectedCommonDataProperties,
+      ...expectedConnectionProperties,
+      status: "STATUS_REDIRECT",
+      URI: Expect.stringContains("/redirect.sjs?firefox-logo-nightly.svg"),
+      RedirectURI: Expect.stringContains("/firefox-logo-nightly.svg"),
+      contentType: null,
+      redirectType: "Permanent",
+      isHttpToHttpsRedirect: false,
+    };
+
+    Assert.objectContains(
+      parentFirstStopMarker,
+      expectedPropertiesForStopMarker
+    );
+    Assert.objectContainsOnly(parentFirstStopMarker.data, {
+      ...expectedDataPropertiesForStopMarker,
+      // The cache information is missing from the content marker, it's only part
+      // of the parent marker. See Bug 1544821.
+      // Also, because the request races with the cache, these 2 values are valid:
+      // "Missed" when the cache answered before we get a result from the network.
+      // "Unresolved" when we got a response from the network before the cache subsystem.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+
+    Assert.objectContains(
+      contentFirstStopMarker,
+      expectedPropertiesForStopMarker
+    );
+    Assert.objectContainsOnly(
+      contentFirstStopMarker.data,
+      expectedDataPropertiesForStopMarker
+    );
+
+    Assert.objectContains(
+      parentRedirectMarker,
+      expectedPropertiesForRedirectMarker
+    );
+    Assert.objectContainsOnly(parentRedirectMarker.data, {
+      ...expectedDataPropertiesForRedirectMarker,
+      redirectId: parentSecondStopMarker.data.id,
+      // See above for the full explanation about the cache property.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+
+    Assert.objectContains(
+      contentRedirectMarker,
+      expectedPropertiesForRedirectMarker
+    );
+    Assert.objectContainsOnly(contentRedirectMarker.data, {
+      ...expectedDataPropertiesForRedirectMarker,
+      redirectId: contentSecondStopMarker.data.id,
+    });
+
+    Assert.objectContains(
+      parentSecondStopMarker,
+      expectedPropertiesForStopMarker
+    );
+    Assert.objectContainsOnly(parentSecondStopMarker.data, {
+      ...expectedDataPropertiesForStopMarker,
+      // The "count" property is absent from the content marker.
+      count: Expect.number(),
+      // See above for the full explanation about the cache property.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+
+    Assert.objectContains(
+      contentSecondStopMarker,
+      expectedPropertiesForStopMarker
+    );
+    Assert.objectContainsOnly(
+      contentSecondStopMarker.data,
+      expectedDataPropertiesForStopMarker
+    );
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_cache_first.js b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_cache_first.js
new file mode 100644
index 0000000000..4b715efa1c
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_cache_first.js
@@ -0,0 +1,388 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test a caching service worker. This service worker will
+ * fetch and store requests at install time, and serve them when the page
+ * requests them.
+ */
+
+const serviceWorkerFileName = "serviceworker_cache_first.js";
+registerCleanupFunction(() => SpecialPowers.removeAllServiceWorkerData());
+
+add_task(async function test_network_markers_service_worker_setup() {
+  // Disabling cache makes the result more predictable. Also this makes things
+  // simpler when dealing with service workers.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_service_worker_register() {
+  // In this first step, we request an HTML page that will register a service
+  // worker. We'll wait until the service worker is fully installed before
+  // checking various things.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_register.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    await SpecialPowers.spawn(
+      contentBrowser,
+      [serviceWorkerFileName],
+      async function(serviceWorkerFileName) {
+        await content.wrappedJSObject.registerServiceWorkerAndWait(
+          serviceWorkerFileName
+        );
+      }
+    );
+
+    const {
+      parentThread,
+      contentThread,
+      profile,
+    } = await stopProfilerNowAndGetThreads(contentPid);
+
+    // The service worker work happens in a third "thread" or process, let's try
+    // to find it.
+    // Currently the fetches happen on the main thread for the content process,
+    // this may change in the future and we may have to adapt this function.
+    // Also please note this isn't necessarily the same content process as the
+    // ones for the tab.
+    const { serviceWorkerParentThread } = findServiceWorkerThreads(profile);
+
+    // Here are a few sanity checks.
+    ok(
+      serviceWorkerParentThread,
+      "We should find a thread for the service worker."
+    );
+
+    Assert.notEqual(
+      serviceWorkerParentThread.pid,
+      parentThread.pid,
+      "We should have a different pid than the parent thread."
+    );
+    Assert.notEqual(
+      serviceWorkerParentThread.tid,
+      parentThread.tid,
+      "We should have a different tid than the parent thread."
+    );
+
+    // Let's make sure we actually have a registered service workers.
+    const workers = await SpecialPowers.registeredServiceWorkers();
+    Assert.equal(
+      workers.length,
+      1,
+      "One service worker should be properly registered."
+    );
+
+    // By logging a few information about the threads we make debugging easier.
+    logInformationForThread("parentThread information", parentThread);
+    logInformationForThread("contentThread information", contentThread);
+    logInformationForThread(
+      "serviceWorkerParentThread information",
+      serviceWorkerParentThread
+    );
+
+    // Now let's check the marker payloads.
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread)
+      // When we load a page, Firefox will check the service worker freshness
+      // after a few seconds. So when the test lasts a long time (with some test
+      // environments) we might see spurious markers about that that we're not
+      // interesting in in this part of the test. They're only present in the
+      // parent process.
+      .filter(marker => !marker.data.URI.includes(serviceWorkerFileName));
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    const serviceWorkerNetworkMarkers = getInflatedNetworkMarkers(
+      serviceWorkerParentThread
+    );
+
+    // Some more logs for debugging purposes.
+    info(
+      "Parent network markers: " + JSON.stringify(parentNetworkMarkers, null, 2)
+    );
+    info(
+      "Content network markers: " +
+        JSON.stringify(contentNetworkMarkers, null, 2)
+    );
+    info(
+      "Serviceworker network markers: " +
+        JSON.stringify(serviceWorkerNetworkMarkers, null, 2)
+    );
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+    const serviceWorkerPairs = getPairsOfNetworkMarkers(
+      serviceWorkerNetworkMarkers
+    );
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+    serviceWorkerPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the service worker process.`
+      )
+    );
+
+    // Let's look at all pairs and make sure we requested all expected files.
+    const parentStopMarkers = parentPairs.map(([_, stopMarker]) => stopMarker);
+    const serviceWorkerStopMarkers = serviceWorkerPairs.map(
+      ([_, stopMarker]) => stopMarker
+    );
+
+    // These are the files cached by the service worker. We should see markers
+    // for both the parent thread and the service worker thread.
+    const expectedFiles = [
+      "serviceworker_page.html",
+      "firefox-logo-nightly.svg",
+    ].map(filename => `${BASE_URL_HTTPS}serviceworkers/${filename}`);
+
+    for (const expectedFile of expectedFiles) {
+      info(
+        `Checking if "${expectedFile}" is present in the network markers in both processes.`
+      );
+      const parentMarker = parentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+      const serviceWorkerMarker = serviceWorkerStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+
+      const expectedProperties = {
+        name: Expect.stringMatches(
+          `Load \\d+:.*${escapeStringRegexp(expectedFile)}`
+        ),
+        data: Expect.objectContains({
+          status: "STATUS_STOP",
+          URI: expectedFile,
+          requestMethod: "GET",
+          contentType: Expect.stringMatches(/^(text\/html|image\/svg\+xml)$/),
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          domainLookupStart: Expect.number(),
+          domainLookupEnd: Expect.number(),
+          connectStart: Expect.number(),
+          tcpConnectEnd: Expect.number(),
+          connectEnd: Expect.number(),
+          requestStart: Expect.number(),
+          responseStart: Expect.number(),
+          responseEnd: Expect.number(),
+          id: Expect.number(),
+          count: Expect.number(),
+          pri: Expect.number(),
+        }),
+      };
+
+      Assert.objectContains(parentMarker, expectedProperties);
+      Assert.objectContains(serviceWorkerMarker, expectedProperties);
+    }
+  });
+});
+
+add_task(async function test_network_markers_service_worker_use() {
+  // In this test we request an HTML file that itself contains resources that
+  // are redirected.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_page.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    // By logging a few information about the threads we make debugging easier.
+    logInformationForThread("parentThread information", parentThread);
+    logInformationForThread("contentThread information", contentThread);
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread)
+      // When we load a page, Firefox will check the service worker freshness
+      // after a few seconds. So when the test lasts a long time (with some test
+      // environments) we might see spurious markers about that that we're not
+      // interesting in in this part of the test. They're only present in the
+      // parent process.
+      .filter(marker => !marker.data.URI.includes(serviceWorkerFileName));
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+
+    // Here are some logs to ease debugging.
+    info(
+      "Parent network markers: " + JSON.stringify(parentNetworkMarkers, null, 2)
+    );
+    info(
+      "Content network markers: " +
+        JSON.stringify(contentNetworkMarkers, null, 2)
+    );
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+
+    // These are the files cached by the service worker. We should see markers
+    // for the parent thread and the content thread.
+    const expectedFiles = [
+      "serviceworker_page.html",
+      "firefox-logo-nightly.svg",
+    ].map(filename => `${BASE_URL_HTTPS}serviceworkers/${filename}`);
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+
+    // Let's look at all pairs and make sure we requested all expected files.
+    const parentEndMarkers = parentPairs.map(([_, endMarker]) => endMarker);
+    const contentStopMarkers = contentPairs.map(
+      ([_, stopMarker]) => stopMarker
+    );
+
+    Assert.equal(
+      parentEndMarkers.length,
+      expectedFiles.length * 2, // one redirect + one stop
+      "There should be twice as many end markers in the parent process as requested files."
+    );
+    Assert.equal(
+      contentStopMarkers.length,
+      expectedFiles.length,
+      "There should be as many stop markers in the content process as requested files."
+    );
+
+    for (const [i, expectedFile] of expectedFiles.entries()) {
+      info(
+        `Checking if "${expectedFile}" if present in the network markers in both processes.`
+      );
+      const [parentRedirectMarker, parentStopMarker] = parentEndMarkers.filter(
+        marker => marker.data.URI === expectedFile
+      );
+      const contentMarker = contentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+
+      const commonDataProperties = {
+        type: "Network",
+        URI: expectedFile,
+        requestMethod: "GET",
+        contentType: Expect.stringMatches(/^(text\/html|image\/svg\+xml)$/),
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+      };
+
+      const expectedProperties = {
+        name: Expect.stringMatches(
+          `Load \\d+:.*${escapeStringRegexp(expectedFile)}`
+        ),
+      };
+
+      Assert.objectContains(parentRedirectMarker, expectedProperties);
+      Assert.objectContains(parentStopMarker, expectedProperties);
+      Assert.objectContains(contentMarker, expectedProperties);
+      if (i === 0) {
+        // This is the top level navigation, the HTML file.
+        Assert.objectContainsOnly(parentRedirectMarker.data, {
+          ...commonDataProperties,
+          status: "STATUS_REDIRECT",
+          contentType: null,
+          cache: "Unresolved",
+          RedirectURI: expectedFile,
+          redirectType: "Internal",
+          redirectId: parentStopMarker.data.id,
+          isHttpToHttpsRedirect: false,
+        });
+
+        Assert.objectContainsOnly(parentStopMarker.data, {
+          ...commonDataProperties,
+          status: "STATUS_STOP",
+        });
+
+        Assert.objectContainsOnly(contentMarker.data, {
+          ...commonDataProperties,
+          status: "STATUS_STOP",
+        });
+      } else {
+        Assert.objectContainsOnly(parentRedirectMarker.data, {
+          ...commonDataProperties,
+          status: "STATUS_REDIRECT",
+          contentType: null,
+          cache: "Unresolved",
+          innerWindowID: Expect.number(),
+          RedirectURI: expectedFile,
+          redirectType: "Internal",
+          redirectId: parentStopMarker.data.id,
+          isHttpToHttpsRedirect: false,
+        });
+
+        Assert.objectContainsOnly(
+          parentStopMarker.data,
+          // Note: in the future we may have more properties. We're using the
+          // "Only" flavor of the matcher so that we don't forget to update this
+          // test when this changes.
+          {
+            ...commonDataProperties,
+            innerWindowID: Expect.number(),
+            status: "STATUS_STOP",
+          }
+        );
+
+        Assert.objectContainsOnly(contentMarker.data, {
+          ...commonDataProperties,
+          innerWindowID: Expect.number(),
+          status: "STATUS_STOP",
+        });
+      }
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_fetch_handler.js b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_fetch_handler.js
new file mode 100644
index 0000000000..775e81f565
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_fetch_handler.js
@@ -0,0 +1,218 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test the case of a service worker that has no fetch
+ * handlers. In this case, a fetch is done to the network. There may be
+ * shortcuts in our code in this case, that's why it's important to test it
+ * separately.
+ */
+
+const serviceWorkerFileName = "serviceworker_no_fetch_handler.js";
+registerCleanupFunction(() => SpecialPowers.removeAllServiceWorkerData());
+
+add_task(async function test_network_markers_service_worker_setup() {
+  // Disabling cache makes the result more predictable. Also this makes things
+  // simpler when dealing with service workers.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_service_worker_register() {
+  // In this first step, we request an HTML page that will register a service
+  // worker. We'll wait until the service worker is fully installed before
+  // checking various things.
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_register.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    await SpecialPowers.spawn(
+      contentBrowser,
+      [serviceWorkerFileName],
+      async function(serviceWorkerFileName) {
+        await content.wrappedJSObject.registerServiceWorkerAndWait(
+          serviceWorkerFileName
+        );
+      }
+    );
+
+    // Let's make sure we actually have a registered service workers.
+    const workers = await SpecialPowers.registeredServiceWorkers();
+    Assert.equal(
+      workers.length,
+      1,
+      "One service worker should be properly registered."
+    );
+  });
+});
+
+add_task(async function test_network_markers_service_worker_use() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_page.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    // By logging a few information about the threads we make debugging easier.
+    logInformationForThread("parentThread information", parentThread);
+    logInformationForThread("contentThread information", contentThread);
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread)
+      // When we load a page, Firefox will check the service worker freshness
+      // after a few seconds. So when the test lasts a long time (with some test
+      // environments) we might see spurious markers about that that we're not
+      // interesting in in this part of the test. They're only present in the
+      // parent process.
+      .filter(marker => !marker.data.URI.includes(serviceWorkerFileName));
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+
+    // Here are some logs to ease debugging.
+    info(
+      "Parent network markers:" + JSON.stringify(parentNetworkMarkers, null, 2)
+    );
+    info(
+      "Content network markers:" +
+        JSON.stringify(contentNetworkMarkers, null, 2)
+    );
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+
+    // Let's look at all pairs and make sure we requested all expected files.
+    const parentStopMarkers = parentPairs.map(([_, stopMarker]) => stopMarker);
+    const contentStopMarkers = contentPairs.map(
+      ([_, stopMarker]) => stopMarker
+    );
+
+    // These are the files requested by the page.
+    // We should see markers for the parent thread and the content thread.
+    const expectedFiles = [
+      // Please take care that the first element is the top level navigation, as
+      // this is special-cased below.
+      "serviceworker_page.html",
+      "firefox-logo-nightly.svg",
+    ].map(filename => `${BASE_URL_HTTPS}serviceworkers/${filename}`);
+
+    Assert.equal(
+      parentStopMarkers.length,
+      expectedFiles.length,
+      "There should be as many stop markers in the parent process as requested files."
+    );
+    Assert.equal(
+      contentStopMarkers.length,
+      expectedFiles.length,
+      "There should be as many stop markers in the content process as requested files."
+    );
+
+    for (const [i, expectedFile] of expectedFiles.entries()) {
+      info(
+        `Checking if "${expectedFile}" if present in the network markers in both processes.`
+      );
+      const parentMarker = parentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+      const contentMarker = contentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+
+      const commonProperties = {
+        name: Expect.stringMatches(
+          `Load \\d+:.*${escapeStringRegexp(expectedFile)}`
+        ),
+      };
+      Assert.objectContains(parentMarker, commonProperties);
+      Assert.objectContains(contentMarker, commonProperties);
+
+      // We get the full set of properties in this case, because we do an actual
+      // fetch to the network.
+      const commonDataProperties = {
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: expectedFile,
+        requestMethod: "GET",
+        contentType: Expect.stringMatches(/^(text\/html|image\/svg\+xml)$/),
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+        count: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+      };
+
+      if (i === 0) {
+        // The first marker is special cased: this is the top level navigation
+        // serviceworker_page.html,
+        // and in this case we don't have all the same properties. Especially
+        // the innerWindowID information is missing.
+        Assert.objectContainsOnly(parentMarker.data, {
+          ...commonDataProperties,
+          // Note that the parent process has the "cache" information, but not the content
+          // process. See Bug 1544821.
+          // Also because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+        });
+
+        Assert.objectContainsOnly(contentMarker.data, commonDataProperties);
+      } else {
+        // This is the other file firefox-logo-nightly.svg.
+        Assert.objectContainsOnly(parentMarker.data, {
+          ...commonDataProperties,
+          // Because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+          innerWindowID: Expect.number(),
+        });
+
+        Assert.objectContainsOnly(contentMarker.data, {
+          ...commonDataProperties,
+          innerWindowID: Expect.number(),
+        });
+      }
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_respondWith_in_fetch_handler.js b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_respondWith_in_fetch_handler.js
new file mode 100644
index 0000000000..65686257de
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_no_respondWith_in_fetch_handler.js
@@ -0,0 +1,296 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test the case of a service worker that has a fetch
+ * handler, but no respondWith. In this case, some process called "reset
+ * interception" happens, and the fetch is still carried on by our code. Because
+ * this is a bit of an edge case, it's important to have a test for this case.
+ */
+
+const serviceWorkerFileName =
+  "serviceworker_no_respondWith_in_fetch_handler.js";
+registerCleanupFunction(() => SpecialPowers.removeAllServiceWorkerData());
+
+add_task(async function test_network_markers_service_worker_setup() {
+  // Disabling cache makes the result more predictable. Also this makes things
+  // simpler when dealing with service workers.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_service_worker_register() {
+  // In this first step, we request an HTML page that will register a service
+  // worker. We'll wait until the service worker is fully installed before
+  // checking various things.
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_register.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    await SpecialPowers.spawn(
+      contentBrowser,
+      [serviceWorkerFileName],
+      async function(serviceWorkerFileName) {
+        await content.wrappedJSObject.registerServiceWorkerAndWait(
+          serviceWorkerFileName
+        );
+      }
+    );
+
+    // Let's make sure we actually have a registered service workers.
+    const workers = await SpecialPowers.registeredServiceWorkers();
+    Assert.equal(
+      workers.length,
+      1,
+      "One service worker should be properly registered."
+    );
+  });
+});
+
+add_task(async function test_network_markers_service_worker_use() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_page.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    // By logging a few information about the threads we make debugging easier.
+    logInformationForThread("parentThread information", parentThread);
+    logInformationForThread("contentThread information", contentThread);
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread)
+      // When we load a page, Firefox will check the service worker freshness
+      // after a few seconds. So when the test lasts a long time (with some test
+      // environments) we might see spurious markers about that that we're not
+      // interesting in in this part of the test. They're only present in the
+      // parent process.
+      .filter(marker => !marker.data.URI.includes(serviceWorkerFileName));
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+
+    // Here are some logs to ease debugging.
+    info(
+      "Parent network markers:" + JSON.stringify(parentNetworkMarkers, null, 2)
+    );
+    info(
+      "Content network markers:" +
+        JSON.stringify(contentNetworkMarkers, null, 2)
+    );
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+
+    // Let's look at all pairs and make sure we requested all expected files.
+    // In this test, we should have redirect markers as well as stop markers,
+    // because this case generates internal redirects. We may want to change
+    // that in the future, or handle this specially in the frontend.
+    // Let's create various arrays to help assert.
+
+    const parentEndMarkers = parentPairs.map(([_, stopMarker]) => stopMarker);
+    const parentStopMarkers = parentEndMarkers.filter(
+      marker => marker.data.status === "STATUS_STOP"
+    );
+    const parentRedirectMarkers = parentEndMarkers.filter(
+      marker => marker.data.status === "STATUS_REDIRECT"
+    );
+    const contentEndMarkers = contentPairs.map(([_, stopMarker]) => stopMarker);
+    const contentStopMarkers = contentEndMarkers.filter(
+      marker => marker.data.status === "STATUS_STOP"
+    );
+    const contentRedirectMarkers = contentEndMarkers.filter(
+      marker => marker.data.status === "STATUS_REDIRECT"
+    );
+
+    // These are the files requested by the page.
+    // We should see markers for the parent thread and the content thread.
+    const expectedFiles = [
+      // Please take care that the first element is the top level navigation, as
+      // this is special-cased below.
+      "serviceworker_page.html",
+      "firefox-logo-nightly.svg",
+    ].map(filename => `${BASE_URL_HTTPS}serviceworkers/${filename}`);
+
+    Assert.equal(
+      parentStopMarkers.length,
+      expectedFiles.length,
+      "There should be as many stop markers in the parent process as requested files."
+    );
+    Assert.equal(
+      parentRedirectMarkers.length,
+      expectedFiles.length * 2, // http -> intercepted, intercepted -> http
+      "There should be twice as many redirect markers in the parent process as requested files."
+    );
+    Assert.equal(
+      contentStopMarkers.length,
+      expectedFiles.length,
+      "There should be as many stop markers in the content process as requested files."
+    );
+    // Note: there will no redirect markers in the content process for
+    // ServiceWorker fallbacks request to network.
+    // See Bug 1793940.
+    Assert.equal(
+      contentRedirectMarkers.length,
+      0,
+      "There should be no redirect markers in the content process than requested files."
+    );
+
+    for (const [i, expectedFile] of expectedFiles.entries()) {
+      info(
+        `Checking if "${expectedFile}" if present in the network markers in both processes.`
+      );
+      const [
+        parentRedirectMarkerIntercept,
+        parentRedirectMarkerReset,
+      ] = parentRedirectMarkers.filter(
+        marker => marker.data.URI === expectedFile
+      );
+      const parentStopMarker = parentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+      const contentStopMarker = contentStopMarkers.find(
+        marker => marker.data.URI === expectedFile
+      );
+
+      const commonProperties = {
+        name: Expect.stringMatches(
+          `Load \\d+:.*${escapeStringRegexp(expectedFile)}`
+        ),
+      };
+      Assert.objectContains(parentRedirectMarkerIntercept, commonProperties);
+      Assert.objectContains(parentRedirectMarkerReset, commonProperties);
+      Assert.objectContains(parentStopMarker, commonProperties);
+      Assert.objectContains(contentStopMarker, commonProperties);
+      // Note: there's no check for the contentRedirectMarker, because there's
+      // no marker for a top level navigation redirect in the content process.
+
+      // We get the full set of properties in this case, because we do an actual
+      // fetch to the network.
+      const commonDataProperties = {
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: expectedFile,
+        requestMethod: "GET",
+        contentType: Expect.stringMatches(/^(text\/html|image\/svg\+xml)$/),
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+        count: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+      };
+
+      const commonRedirectProperties = {
+        type: "Network",
+        status: "STATUS_REDIRECT",
+        URI: expectedFile,
+        RedirectURI: expectedFile,
+        requestMethod: "GET",
+        contentType: null,
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+        redirectType: "Internal",
+        isHttpToHttpsRedirect: false,
+      };
+
+      if (i === 0) {
+        // The first marker is special cased: this is the top level navigation
+        // serviceworker_page.html,
+        // and in this case we don't have all the same properties. Especially
+        // the innerWindowID information is missing.
+        Assert.objectContainsOnly(parentStopMarker.data, {
+          ...commonDataProperties,
+          // Note that the parent process has the "cache" information, but not the content
+          // process. See Bug 1544821.
+          // Also, because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+        });
+        Assert.objectContainsOnly(contentStopMarker.data, commonDataProperties);
+
+        Assert.objectContainsOnly(parentRedirectMarkerIntercept.data, {
+          ...commonRedirectProperties,
+          redirectId: parentRedirectMarkerReset.data.id,
+          cache: "Unresolved",
+        });
+        Assert.objectContainsOnly(parentRedirectMarkerReset.data, {
+          ...commonRedirectProperties,
+          redirectId: parentStopMarker.data.id,
+        });
+
+        // Note: there's no check for the contentRedirectMarker, because there's
+        // no marker for a top level navigation redirect in the content process.
+      } else {
+        // This is the other file firefox-logo-nightly.svg.
+        Assert.objectContainsOnly(parentStopMarker.data, {
+          ...commonDataProperties,
+          // Because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+          innerWindowID: Expect.number(),
+        });
+        Assert.objectContains(contentStopMarker, commonProperties);
+        Assert.objectContainsOnly(contentStopMarker.data, {
+          ...commonDataProperties,
+          innerWindowID: Expect.number(),
+        });
+
+        Assert.objectContainsOnly(parentRedirectMarkerIntercept.data, {
+          ...commonRedirectProperties,
+          innerWindowID: Expect.number(),
+          redirectId: parentRedirectMarkerReset.data.id,
+          cache: "Unresolved",
+        });
+        Assert.objectContainsOnly(parentRedirectMarkerReset.data, {
+          ...commonRedirectProperties,
+          innerWindowID: Expect.number(),
+          redirectId: parentStopMarker.data.id,
+        });
+      }
+    }
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_synthetized_response.js b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_synthetized_response.js
new file mode 100644
index 0000000000..41690e11a6
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_serviceworker_synthetized_response.js
@@ -0,0 +1,558 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test a service worker that returns a synthetized response.
+ * This means the service worker will make up a response by itself.
+ */
+
+const serviceWorkerFileName = "serviceworker_synthetized_response.js";
+registerCleanupFunction(() => SpecialPowers.removeAllServiceWorkerData());
+
+add_task(async function test_network_markers_service_worker_setup() {
+  // Disabling cache makes the result more predictable. Also this makes things
+  // simpler when dealing with service workers.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_service_worker_register() {
+  // In this first step, we request an HTML page that will register a service
+  // worker. We'll wait until the service worker is fully installed before
+  // checking various things.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_register.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    await SpecialPowers.spawn(
+      contentBrowser,
+      [serviceWorkerFileName],
+      async function(serviceWorkerFileName) {
+        await content.wrappedJSObject.registerServiceWorkerAndWait(
+          serviceWorkerFileName
+        );
+      }
+    );
+
+    // Let's make sure we actually have a registered service workers.
+    const workers = await SpecialPowers.registeredServiceWorkers();
+    Assert.equal(
+      workers.length,
+      1,
+      "One service worker should be properly registered."
+    );
+  });
+});
+
+add_task(async function test_network_markers_service_worker_use() {
+  // In this test, we'll first load a plain html file, then do some fetch
+  // requests in the context of the page. One request is served with a
+  // synthetized response, the other request is served with a real "fetch" done
+  // by the service worker.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = `${BASE_URL_HTTPS}serviceworkers/serviceworker_simple.html`;
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    await SpecialPowers.spawn(contentBrowser, [], async () => {
+      // This request is served directly by the service worker as a synthetized response.
+      await content
+        .fetch("firefox-generated.svg")
+        .then(res => res.arrayBuffer());
+
+      // This request is served by a fetch done inside the service worker.
+      await content
+        .fetch("firefox-logo-nightly.svg")
+        .then(res => res.arrayBuffer());
+    });
+
+    const {
+      parentThread,
+      contentThread,
+      profile,
+    } = await stopProfilerNowAndGetThreads(contentPid);
+
+    // The service worker work happens in a third "thread" or process, let's try
+    // to find it.
+    // Currently the fetches happen on the main thread for the content process,
+    // this may change in the future and we may have to adapt this function.
+    // Also please note this isn't necessarily the same content process as the
+    // ones for the tab.
+    const { serviceWorkerParentThread } = findServiceWorkerThreads(profile);
+
+    ok(
+      serviceWorkerParentThread,
+      "We should find a thread for the service worker."
+    );
+
+    // By logging a few information about the threads we make debugging easier.
+    logInformationForThread("parentThread information", parentThread);
+    logInformationForThread("contentThread information", contentThread);
+    logInformationForThread(
+      "serviceWorkerParentThread information",
+      serviceWorkerParentThread
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread)
+      // When we load a page, Firefox will check the service worker freshness
+      // after a few seconds. So when the test lasts a long time (with some test
+      // environments) we might see spurious markers about that that we're not
+      // interesting in in this part of the test. They're only present in the
+      // parent process.
+      .filter(marker => !marker.data.URI.includes(serviceWorkerFileName));
+
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    const serviceWorkerNetworkMarkers = getInflatedNetworkMarkers(
+      serviceWorkerParentThread
+    );
+
+    // Some more logs for debugging purposes.
+    info(
+      "Parent network markers: " + JSON.stringify(parentNetworkMarkers, null, 2)
+    );
+    info(
+      "Content network markers: " +
+        JSON.stringify(contentNetworkMarkers, null, 2)
+    );
+    info(
+      "Serviceworker network markers: " +
+        JSON.stringify(serviceWorkerNetworkMarkers, null, 2)
+    );
+
+    const parentPairs = getPairsOfNetworkMarkers(parentNetworkMarkers);
+    const contentPairs = getPairsOfNetworkMarkers(contentNetworkMarkers);
+    const serviceWorkerPairs = getPairsOfNetworkMarkers(
+      serviceWorkerNetworkMarkers
+    );
+
+    // First, make sure we properly matched all start with stop markers. This
+    // means that both arrays should contain only arrays of 2 elements.
+    parentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the parent process.`
+      )
+    );
+
+    contentPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the content process.`
+      )
+    );
+    serviceWorkerPairs.forEach(pair =>
+      Assert.equal(
+        pair.length,
+        2,
+        `For the URL ${pair[0].data.URI} we should get 2 markers in the service worker process.`
+      )
+    );
+
+    // Let's look at all pairs and make sure we requested all expected files.
+    // In this test, we should have redirect markers as well as stop markers,
+    // because this case generates internal redirects.
+    // Let's create various arrays to help assert.
+
+    let parentStopMarkers = parentPairs.map(([_, stopMarker]) => stopMarker);
+    const contentStopMarkers = contentPairs.map(
+      ([_, stopMarker]) => stopMarker
+    );
+    const serviceWorkerStopMarkers = serviceWorkerPairs.map(
+      ([_, stopMarker]) => stopMarker
+    );
+
+    // In this test we have very different results in the various threads, so
+    // we'll assert every case separately.
+    // A simple function to help constructing better assertions:
+    const fullUrl = filename => `${BASE_URL_HTTPS}serviceworkers/${filename}`;
+
+    {
+      // In the parent process, we have 8 network markers:
+      // - twice the html file -- because it's not cached by the SW, we get the
+      //   marker both for the initial request and for the request initied from the
+      //   SW.
+      // - twice the firefox svg file -- similar situation
+      // - once the generated svg file -- this one isn't fetched by the SW but
+      //   rather forged directly, so there's no "second fetch", and thus we have
+      //   only one marker.
+      // - for each of these files, we have first an internal redirect from the
+      //   main channel to the service worker. => 3 redirect markers more.
+      Assert.equal(
+        parentStopMarkers.length,
+        8, // 3 html files, 3 firefox svg files, 2 generated svg file
+        "There should be 8 stop markers in the parent process."
+      );
+
+      // The "1" requests are the initial requests that are intercepted, coming
+      // from the web page, while the "2" requests are requests to the network,
+      // coming from the service worker. The 1 were requested before 2, 2 ends
+      // before 1.
+      // "Intercept" requests are the internal redirects from the main channel
+      // to the service worker. They happen before others.
+      const [
+        htmlFetchIntercept,
+        htmlFetch1,
+        htmlFetch2,
+        generatedSvgIntercept,
+        generatedSvgFetch,
+        firefoxSvgIntercept,
+        firefoxSvgFetch1,
+        firefoxSvgFetch2,
+      ] = parentStopMarkers;
+
+      /* ----- /HTML FILE ---- */
+      Assert.objectContains(htmlFetchIntercept, {
+        name: Expect.stringMatches(/Load \d+:.*serviceworker_simple.html/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_REDIRECT",
+          URI: fullUrl("serviceworker_simple.html"),
+          requestMethod: "GET",
+          contentType: null,
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+          redirectId: htmlFetch1.data.id,
+          redirectType: "Internal",
+          isHttpToHttpsRedirect: false,
+          RedirectURI: fullUrl("serviceworker_simple.html"),
+          cache: "Unresolved",
+        }),
+      });
+
+      Assert.objectContains(htmlFetch1, {
+        name: Expect.stringMatches(/Load \d+:.*serviceworker_simple.html/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_STOP",
+          URI: fullUrl("serviceworker_simple.html"),
+          requestMethod: "GET",
+          contentType: "text/html",
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+        }),
+      });
+      Assert.objectContains(htmlFetch2, {
+        name: Expect.stringMatches(/Load \d+:.*serviceworker_simple.html/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_STOP",
+          URI: fullUrl("serviceworker_simple.html"),
+          requestMethod: "GET",
+          contentType: "text/html",
+          // Because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          domainLookupStart: Expect.number(),
+          domainLookupEnd: Expect.number(),
+          connectStart: Expect.number(),
+          tcpConnectEnd: Expect.number(),
+          connectEnd: Expect.number(),
+          requestStart: Expect.number(),
+          responseStart: Expect.number(),
+          responseEnd: Expect.number(),
+          id: Expect.number(),
+          count: Expect.number(),
+          pri: Expect.number(),
+        }),
+      });
+      /* ----- /HTML FILE ---- */
+
+      /* ----- GENERATED SVG FILE ---- */
+      Assert.objectContains(generatedSvgIntercept, {
+        name: Expect.stringMatches(/Load \d+:.*firefox-generated.svg/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_REDIRECT",
+          URI: fullUrl("firefox-generated.svg"),
+          requestMethod: "GET",
+          contentType: null,
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+          redirectId: generatedSvgFetch.data.id,
+          redirectType: "Internal",
+          isHttpToHttpsRedirect: false,
+          RedirectURI: fullUrl("firefox-generated.svg"),
+          cache: "Unresolved",
+          innerWindowID: Expect.number(),
+        }),
+      });
+      Assert.objectContains(generatedSvgFetch, {
+        name: Expect.stringMatches(/Load \d+:.*firefox-generated.svg/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_STOP",
+          URI: fullUrl("firefox-generated.svg"),
+          requestMethod: "GET",
+          contentType: "image/svg+xml",
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+          innerWindowID: Expect.number(),
+        }),
+      });
+      /* ----- ∕GENERATED SVG FILE ---- */
+      /* ----- REQUESTED SVG FILE ---- */
+      Assert.objectContains(firefoxSvgIntercept, {
+        name: Expect.stringMatches(/Load \d+:.*firefox-logo-nightly.svg/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_REDIRECT",
+          URI: fullUrl("firefox-logo-nightly.svg"),
+          requestMethod: "GET",
+          contentType: null,
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+          redirectId: firefoxSvgFetch1.data.id,
+          redirectType: "Internal",
+          isHttpToHttpsRedirect: false,
+          RedirectURI: fullUrl("firefox-logo-nightly.svg"),
+          cache: "Unresolved",
+          innerWindowID: Expect.number(),
+        }),
+      });
+      Assert.objectContains(firefoxSvgFetch1, {
+        name: Expect.stringMatches(/Load \d+:.*firefox-logo-nightly.svg/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_STOP",
+          URI: fullUrl("firefox-logo-nightly.svg"),
+          requestMethod: "GET",
+          contentType: "image/svg+xml",
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          id: Expect.number(),
+          pri: Expect.number(),
+          innerWindowID: Expect.number(),
+        }),
+      });
+      Assert.objectContains(firefoxSvgFetch2, {
+        name: Expect.stringMatches(/Load \d+:.*firefox-logo-nightly.svg/),
+        data: Expect.objectContainsOnly({
+          type: "Network",
+          status: "STATUS_STOP",
+          URI: fullUrl("firefox-logo-nightly.svg"),
+          requestMethod: "GET",
+          contentType: "image/svg+xml",
+          // Because the request races with the cache, these 2 values are valid:
+          // "Missed" when the cache answered before we get a result from the network.
+          // "Unresolved" when we got a response from the network before the cache subsystem.
+          cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+          startTime: Expect.number(),
+          endTime: Expect.number(),
+          domainLookupStart: Expect.number(),
+          domainLookupEnd: Expect.number(),
+          connectStart: Expect.number(),
+          tcpConnectEnd: Expect.number(),
+          connectEnd: Expect.number(),
+          requestStart: Expect.number(),
+          responseStart: Expect.number(),
+          responseEnd: Expect.number(),
+          id: Expect.number(),
+          count: Expect.number(),
+          pri: Expect.number(),
+          // Note: no innerWindowID here, is that a bug?
+        }),
+      });
+      /* ----- ∕REQUESTED SVG FILE ---- */
+    }
+
+    // It's possible that the service worker thread IS the content thread, in
+    // that case we'll get all markers in the same thread.
+    // The "1" requests are the initial requests that are intercepted, coming
+    // from the web page, while the "2" requests are the requests coming from
+    // the service worker.
+    let htmlFetch1,
+      htmlFetch2,
+      generatedSvgFetch1,
+      firefoxSvgFetch1,
+      firefoxSvgFetch2;
+
+    // First, let's handle the case where the threads are different:
+    if (serviceWorkerParentThread !== contentThread) {
+      // In the content process (that is the process for the web page), we have
+      // 3 network markers:
+      // - 1 for the HTML page
+      // - 1 for the generated svg file
+      // - 1 for the firefox svg file
+      // Indeed, the service worker interception is invisible from the context
+      // of the web page, so we just get 3 "normal" requests. However these
+      // requests will miss all timing information, because they're hidden by
+      // the service worker interception. We may want to fix this...
+      Assert.equal(
+        contentStopMarkers.length,
+        3, // 1 for each file
+        "There should be 3 stop markers in the content process."
+      );
+
+      [htmlFetch1, generatedSvgFetch1, firefoxSvgFetch1] = contentStopMarkers;
+
+      // In the service worker parent thread, we have 2 network markers:
+      // - the HTML file
+      // - the firefox SVG file.
+      // Remember that the generated SVG file is returned directly by the SW.
+      Assert.equal(
+        serviceWorkerStopMarkers.length,
+        2,
+        "There should be 2 stop markers in the service worker thread."
+      );
+
+      [htmlFetch2, firefoxSvgFetch2] = serviceWorkerStopMarkers;
+    } else {
+      // Else case: the service worker parent thread IS the content thread
+      // (note: this is always the case with fission). In that case all network
+      // markers tested in the above block are together in the same object.
+      Assert.equal(
+        contentStopMarkers.length,
+        5,
+        "There should be 5 stop markers in the combined process (containing both the content page and the service worker)"
+      );
+
+      // Because of how the test is done, these markers are ordered by the
+      // position of the START markers.
+      [
+        // For the htmlFetch request, note that 2 is before 1, because that's
+        // the top level navigation. Indeed for the top level navigation
+        // everything happens first in the main process, possibly before a
+        // content process even exists, and the content process is merely
+        // notified at the end.
+        htmlFetch2,
+        htmlFetch1,
+        generatedSvgFetch1,
+        firefoxSvgFetch1,
+        firefoxSvgFetch2,
+      ] = contentStopMarkers;
+    }
+
+    // Let's test first the markers coming from the content page.
+    Assert.objectContains(htmlFetch1, {
+      name: Expect.stringMatches(/Load \d+:.*serviceworker_simple.html/),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: fullUrl("serviceworker_simple.html"),
+        requestMethod: "GET",
+        contentType: "text/html",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+      }),
+    });
+    Assert.objectContains(generatedSvgFetch1, {
+      name: Expect.stringMatches(/Load \d+:.*firefox-generated.svg/),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: fullUrl("firefox-generated.svg"),
+        requestMethod: "GET",
+        contentType: "image/svg+xml",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+        innerWindowID: Expect.number(),
+      }),
+    });
+    Assert.objectContains(firefoxSvgFetch1, {
+      name: Expect.stringMatches(/Load \d+:.*firefox-logo-nightly.svg/),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: fullUrl("firefox-logo-nightly.svg"),
+        requestMethod: "GET",
+        contentType: "image/svg+xml",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        pri: Expect.number(),
+        innerWindowID: Expect.number(),
+      }),
+    });
+
+    // Now let's test the markers coming from the service worker.
+    Assert.objectContains(htmlFetch2, {
+      name: Expect.stringMatches(/Load \d+:.*serviceworker_simple.html/),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: fullUrl("serviceworker_simple.html"),
+        requestMethod: "GET",
+        contentType: "text/html",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+        id: Expect.number(),
+        count: Expect.number(),
+        pri: Expect.number(),
+        // Note: no innerWindowID here, is that a bug?
+        // Note: no cache either, this is bug 1544821.
+      }),
+    });
+
+    Assert.objectContains(firefoxSvgFetch2, {
+      name: Expect.stringMatches(/Load \d+:.*firefox-logo-nightly.svg/),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_STOP",
+        URI: fullUrl("firefox-logo-nightly.svg"),
+        requestMethod: "GET",
+        contentType: "image/svg+xml",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+        id: Expect.number(),
+        count: Expect.number(),
+        pri: Expect.number(),
+        // Note: no innerWindowID here, is that a bug?
+        // Note: no cache either, this is bug 1544821.
+      }),
+    });
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_simple.js b/tools/profiler/tests/browser/browser_test_marker_network_simple.js
new file mode 100644
index 0000000000..15894305a7
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_simple.js
@@ -0,0 +1,81 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly
+ */
+add_task(async function test_network_markers() {
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = BASE_URL + "simple.html?cacheBust=" + Math.random();
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    info(JSON.stringify(parentNetworkMarkers, null, 2));
+    info(JSON.stringify(contentNetworkMarkers, null, 2));
+
+    Assert.equal(
+      parentNetworkMarkers.length,
+      2,
+      `We should get a pair of network markers in the parent thread.`
+    );
+    Assert.equal(
+      contentNetworkMarkers.length,
+      2,
+      `We should get a pair of network markers in the content thread.`
+    );
+
+    const parentStopMarker = parentNetworkMarkers[1];
+    const contentStopMarker = contentNetworkMarkers[1];
+
+    const expectedProperties = {
+      name: Expect.stringMatches(`Load \\d+:.*${escapeStringRegexp(url)}`),
+      data: Expect.objectContains({
+        status: "STATUS_STOP",
+        URI: url,
+        requestMethod: "GET",
+        contentType: "text/html",
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        domainLookupStart: Expect.number(),
+        domainLookupEnd: Expect.number(),
+        connectStart: Expect.number(),
+        tcpConnectEnd: Expect.number(),
+        connectEnd: Expect.number(),
+        requestStart: Expect.number(),
+        responseStart: Expect.number(),
+        responseEnd: Expect.number(),
+        id: Expect.number(),
+        count: Expect.number(),
+        pri: Expect.number(),
+      }),
+    };
+
+    Assert.objectContains(parentStopMarker, expectedProperties);
+    // The cache information is missing from the content marker, it's only part
+    // of the parent marker. See Bug 1544821.
+    Assert.objectContains(parentStopMarker.data, {
+      // Because the request races with the cache, these 2 values are valid:
+      // "Missed" when the cache answered before we get a result from the network.
+      // "Unresolved" when we got a response from the network before the cache subsystem.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+    Assert.objectContains(contentStopMarker, expectedProperties);
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_marker_network_sts.js b/tools/profiler/tests/browser/browser_test_marker_network_sts.js
new file mode 100644
index 0000000000..26f2a1c756
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_marker_network_sts.js
@@ -0,0 +1,130 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we emit network markers accordingly.
+ * In this file we'll test that we behave properly with STS redirections.
+ */
+
+add_task(async function test_network_markers_service_worker_setup() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      // Disabling cache makes the result more predictable especially in verify mode.
+      ["browser.cache.disk.enable", false],
+      ["browser.cache.memory.enable", false],
+      // We want to test upgrading requests
+      ["dom.security.https_only_mode", true],
+    ],
+  });
+});
+
+add_task(async function test_network_markers_redirect_to_https() {
+  // In this test, we request an HTML page with http that gets redirected to https.
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  startProfilerForMarkerTests();
+
+  const url = BASE_URL + "simple.html";
+  const targetUrl = BASE_URL_HTTPS + "simple.html";
+
+  await BrowserTestUtils.withNewTab(url, async contentBrowser => {
+    const contentPid = await SpecialPowers.spawn(
+      contentBrowser,
+      [],
+      () => Services.appinfo.processID
+    );
+
+    const { parentThread, contentThread } = await stopProfilerNowAndGetThreads(
+      contentPid
+    );
+
+    const parentNetworkMarkers = getInflatedNetworkMarkers(parentThread);
+    const contentNetworkMarkers = getInflatedNetworkMarkers(contentThread);
+    info(JSON.stringify(parentNetworkMarkers, null, 2));
+    info(JSON.stringify(contentNetworkMarkers, null, 2));
+
+    Assert.equal(
+      parentNetworkMarkers.length,
+      4,
+      `We should get 2 pairs of network markers in the parent thread.`
+    );
+
+    /* It looks like that for a redirection for the top level navigation, the
+     * content thread sees the markers for the second request only.
+     * See Bug 1692879. */
+    Assert.equal(
+      contentNetworkMarkers.length,
+      2,
+      `We should get one pair of network markers in the content thread.`
+    );
+
+    const parentRedirectMarker = parentNetworkMarkers[1];
+    const parentStopMarker = parentNetworkMarkers[3];
+    // There's no content redirect marker for the reason outlined above.
+    const contentStopMarker = contentNetworkMarkers[1];
+
+    Assert.objectContains(parentRedirectMarker, {
+      name: Expect.stringMatches(`Load \\d+:.*${escapeStringRegexp(url)}`),
+      data: Expect.objectContainsOnly({
+        type: "Network",
+        status: "STATUS_REDIRECT",
+        URI: url,
+        RedirectURI: targetUrl,
+        requestMethod: "GET",
+        contentType: null,
+        startTime: Expect.number(),
+        endTime: Expect.number(),
+        id: Expect.number(),
+        redirectId: parentStopMarker.data.id,
+        pri: Expect.number(),
+        cache: "Unresolved",
+        redirectType: "Permanent",
+        isHttpToHttpsRedirect: true,
+      }),
+    });
+
+    const expectedProperties = {
+      name: Expect.stringMatches(
+        `Load \\d+:.*${escapeStringRegexp(targetUrl)}`
+      ),
+    };
+    const expectedDataProperties = {
+      type: "Network",
+      status: "STATUS_STOP",
+      URI: targetUrl,
+      requestMethod: "GET",
+      contentType: "text/html",
+      startTime: Expect.number(),
+      endTime: Expect.number(),
+      domainLookupStart: Expect.number(),
+      domainLookupEnd: Expect.number(),
+      connectStart: Expect.number(),
+      tcpConnectEnd: Expect.number(),
+      connectEnd: Expect.number(),
+      requestStart: Expect.number(),
+      responseStart: Expect.number(),
+      responseEnd: Expect.number(),
+      id: Expect.number(),
+      count: Expect.number(),
+      pri: Expect.number(),
+    };
+
+    Assert.objectContains(parentStopMarker, expectedProperties);
+    Assert.objectContains(contentStopMarker, expectedProperties);
+
+    // The cache information is missing from the content marker, it's only part
+    // of the parent marker. See Bug 1544821.
+    Assert.objectContainsOnly(parentStopMarker.data, {
+      ...expectedDataProperties,
+      // Because the request races with the cache, these 2 values are valid:
+      // "Missed" when the cache answered before we get a result from the network.
+      // "Unresolved" when we got a response from the network before the cache subsystem.
+      cache: Expect.stringMatches(/^(Missed|Unresolved)$/),
+    });
+    Assert.objectContainsOnly(contentStopMarker.data, expectedDataProperties);
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_markers_gc_cc.js b/tools/profiler/tests/browser/browser_test_markers_gc_cc.js
new file mode 100644
index 0000000000..a4a94d60cc
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_markers_gc_cc.js
@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async function test_markers_gc_cc() {
+  info("Test GC&CC markers.");
+
+  info("Create a throwaway profile.");
+  await startProfiler({});
+  let tempProfileContainer = { profile: null };
+  tempProfileContainer.profile = await waitSamplingAndStopAndGetProfile();
+
+  info("Restart the profiler.");
+  await startProfiler({});
+
+  info("Throw away the previous profile, which should be garbage-collected.");
+  Assert.equal(
+    typeof tempProfileContainer.profile,
+    "object",
+    "Previously-captured profile should be an object"
+  );
+  delete tempProfileContainer.profile;
+  Assert.equal(
+    typeof tempProfileContainer.profile,
+    "undefined",
+    "Deleted profile should now be undefined"
+  );
+
+  info("Force GC&CC");
+  SpecialPowers.gc();
+  SpecialPowers.forceShrinkingGC();
+  SpecialPowers.forceCC();
+  SpecialPowers.gc();
+  SpecialPowers.forceShrinkingGC();
+  SpecialPowers.forceCC();
+
+  info("Stop the profiler and get the profile.");
+  const profile = await waitSamplingAndStopAndGetProfile();
+
+  const markers = getInflatedMarkerData(profile.threads[0]);
+  Assert.ok(
+    markers.some(({ data }) => data?.type === "GCSlice"),
+    "A GCSlice marker was recorded"
+  );
+  Assert.ok(
+    markers.some(({ data }) => data?.type === "CCSlice"),
+    "A CCSlice marker was recorded"
+  );
+});
diff --git a/tools/profiler/tests/browser/browser_test_markers_parent_process.js b/tools/profiler/tests/browser/browser_test_markers_parent_process.js
new file mode 100644
index 0000000000..28b82f8054
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_markers_parent_process.js
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async function test_markers_parent_process() {
+  info("Test markers that are generated by the browser's parent process.");
+
+  info("Start the profiler in nostacksampling mode.");
+  await startProfiler({ features: ["nostacksampling"] });
+
+  info("Dispatch a DOMEvent");
+  window.dispatchEvent(new Event("synthetic"));
+
+  info("Stop the profiler and get the profile.");
+  const profile = await stopNowAndGetProfile();
+
+  const markers = getInflatedMarkerData(profile.threads[0]);
+  {
+    const domEventStart = markers.find(
+      ({ phase, data }) =>
+        phase === INTERVAL_START && data?.eventType === "synthetic"
+    );
+    const domEventEnd = markers.find(
+      ({ phase, data }) =>
+        phase === INTERVAL_END && data?.eventType === "synthetic"
+    );
+    ok(domEventStart, "A start DOMEvent was generated");
+    ok(domEventEnd, "An end DOMEvent was generated");
+    ok(
+      domEventEnd.data.latency > 0,
+      "DOMEvent had a a latency value generated."
+    );
+    ok(domEventEnd.data.type === "DOMEvent");
+    ok(domEventEnd.name === "DOMEvent");
+  }
+  // Add more marker tests.
+});
diff --git a/tools/profiler/tests/browser/browser_test_profile_capture_by_pid.js b/tools/profiler/tests/browser/browser_test_profile_capture_by_pid.js
new file mode 100644
index 0000000000..3694ffd93e
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_profile_capture_by_pid.js
@@ -0,0 +1,206 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function ProcessHasSamplerThread(process) {
+  return process.threads.some(t => t.name == "SamplerThread");
+}
+
+async function GetPidsWithSamplerThread() {
+  let parentProc = await ChromeUtils.requestProcInfo();
+
+  let pids = parentProc.children
+    .filter(ProcessHasSamplerThread)
+    .map(proc => proc.pid);
+  if (ProcessHasSamplerThread(parentProc)) {
+    pids.unshift(parentProc.pid);
+  }
+  return pids;
+}
+
+// fnFilterWithContentId: Called with content child pid, returns filters to use.
+// E.g.: 123 => ["GeckoMain", "pid:123"], or 123 => ["pid:456"].
+async function test_with_filter(fnFilterWithContentId) {
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info("Open a tab with single_frame.html in it.");
+  const url = BASE_URL + "single_frame.html";
+  return BrowserTestUtils.withNewTab(url, async function(contentBrowser) {
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    Assert.deepEqual(
+      await GetPidsWithSamplerThread(),
+      [],
+      "There should be no SamplerThreads before starting the profiler"
+    );
+
+    info("Start the profiler to test filters including 'pid:<content>'.");
+    await startProfiler({ threads: fnFilterWithContentId(contentPid) });
+
+    let pidsWithSamplerThread = null;
+    await TestUtils.waitForCondition(
+      async function() {
+        let pidsStringBefore = JSON.stringify(pidsWithSamplerThread);
+        pidsWithSamplerThread = await GetPidsWithSamplerThread();
+        return JSON.stringify(pidsWithSamplerThread) == pidsStringBefore;
+      },
+      "Wait for sampler threads to stabilize after profiler start",
+      /* interval (ms) */ 250,
+      /* maxTries */ 10
+    );
+
+    info("Capture the profile data.");
+    const profile = await waitSamplingAndStopAndGetProfile();
+
+    await TestUtils.waitForCondition(async function() {
+      return !(await GetPidsWithSamplerThread()).length;
+    }, "Wait for all sampler threads to stop after profiler stop");
+
+    return { contentPid, pidsWithSamplerThread, profile };
+  });
+}
+
+add_task(async function browser_test_profile_capture_along_with_content_pid() {
+  const {
+    contentPid,
+    pidsWithSamplerThread,
+    profile,
+  } = await test_with_filter(contentPid => ["GeckoMain", "pid:" + contentPid]);
+
+  Assert.greater(
+    pidsWithSamplerThread.length,
+    2,
+    "There should be lots of SamplerThreads after starting the profiler"
+  );
+
+  let contentProcessIndex = profile.processes.findIndex(
+    p => p.threads[0].pid == contentPid
+  );
+  Assert.notEqual(
+    contentProcessIndex,
+    -1,
+    "The content process should be present"
+  );
+
+  // Note: Some threads may not be registered, so we can't expect that many. But
+  // 10 is much more than the default 4.
+  Assert.greater(
+    profile.processes[contentProcessIndex].threads.length,
+    10,
+    "The content process should have many threads"
+  );
+
+  Assert.equal(
+    profile.threads.length,
+    1,
+    "The parent process should have only one thread"
+  );
+  Assert.equal(
+    profile.threads[0].name,
+    "GeckoMain",
+    "The parent process should have the main thread"
+  );
+});
+
+add_task(async function browser_test_profile_capture_along_with_other_pid() {
+  const parentPid = Services.appinfo.processID;
+  const {
+    contentPid,
+    pidsWithSamplerThread,
+    profile,
+  } = await test_with_filter(contentPid => ["GeckoMain", "pid:" + parentPid]);
+
+  Assert.greater(
+    pidsWithSamplerThread.length,
+    2,
+    "There should be lots of SamplerThreads after starting the profiler"
+  );
+
+  let contentProcessIndex = profile.processes.findIndex(
+    p => p.threads[0].pid == contentPid
+  );
+  Assert.notEqual(
+    contentProcessIndex,
+    -1,
+    "The content process should be present"
+  );
+
+  Assert.equal(
+    profile.processes[contentProcessIndex].threads.length,
+    1,
+    "The content process should have only one thread"
+  );
+
+  // Note: Some threads may not be registered, so we can't expect that many. But
+  // 10 is much more than the default 4.
+  Assert.greater(
+    profile.threads.length,
+    10,
+    "The parent process should have many threads"
+  );
+});
+
+add_task(async function browser_test_profile_capture_by_only_content_pid() {
+  const parentPid = Services.appinfo.processID;
+  const {
+    contentPid,
+    pidsWithSamplerThread,
+    profile,
+  } = await test_with_filter(contentPid => ["pid:" + contentPid]);
+
+  // The sampler thread always runs in the parent process, see bug 1754100.
+  Assert.deepEqual(
+    pidsWithSamplerThread,
+    [parentPid, contentPid],
+    "There should only be SamplerThreads in the parent and the target child"
+  );
+
+  Assert.equal(
+    profile.processes.length,
+    1,
+    "There should only be one child process"
+  );
+  // Note: Some threads may not be registered, so we can't expect that many. But
+  // 10 is much more than the default 4.
+  Assert.greater(
+    profile.processes[0].threads.length,
+    10,
+    "The child process should have many threads"
+  );
+  Assert.equal(
+    profile.processes[0].threads[0].pid,
+    contentPid,
+    "The only child process should be our content"
+  );
+});
+
+add_task(async function browser_test_profile_capture_by_only_parent_pid() {
+  const parentPid = Services.appinfo.processID;
+  const {
+    pidsWithSamplerThread,
+    profile,
+  } = await test_with_filter(contentPid => ["pid:" + parentPid]);
+
+  Assert.deepEqual(
+    pidsWithSamplerThread,
+    [parentPid],
+    "There should only be a SamplerThread in the parent"
+  );
+
+  // Note: Some threads may not be registered, so we can't expect that many. But
+  // 10 is much more than the default 4.
+  Assert.greater(
+    profile.threads.length,
+    10,
+    "The parent process should have many threads"
+  );
+  Assert.equal(
+    profile.processes.length,
+    0,
+    "There should be no child processes"
+  );
+});
diff --git a/tools/profiler/tests/browser/browser_test_profile_fission.js b/tools/profiler/tests/browser/browser_test_profile_fission.js
new file mode 100644
index 0000000000..f3d8016569
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_profile_fission.js
@@ -0,0 +1,196 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+if (SpecialPowers.useRemoteSubframes) {
+  // Bug 1586105: these tests could time out in some extremely slow conditions,
+  // when fission is enabled.
+  // Requesting a longer timeout should make it pass.
+  requestLongerTimeout(2);
+}
+
+add_task(async function test_profile_fission_no_private_browsing() {
+  // Requesting the complete log to be able to debug Bug 1586105.
+  SimpleTest.requestCompleteLog();
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still have some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler();
+
+  info("Open a private window with single_frame.html in it.");
+  const win = await BrowserTestUtils.openNewBrowserWindow({
+    fission: true,
+  });
+
+  try {
+    const url = BASE_URL_HTTPS + "single_frame.html";
+    const contentBrowser = win.gBrowser.selectedBrowser;
+    BrowserTestUtils.loadURI(contentBrowser, url);
+    await BrowserTestUtils.browserLoaded(contentBrowser, false, url);
+
+    const parentPid = Services.appinfo.processID;
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const activeTabID = contentBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const {
+      profile,
+      contentProcess,
+      contentThread,
+    } = await stopProfilerNowAndGetThreads(contentPid);
+
+    Assert.equal(
+      contentThread.isPrivateBrowsing,
+      false,
+      "The content process has the private browsing flag set to false."
+    );
+
+    Assert.equal(
+      contentThread.userContextId,
+      0,
+      "The content process has the information about the container used for this process"
+    );
+
+    info(
+      "Check if the captured page is the one with correct values we created."
+    );
+
+    let pageFound = false;
+    for (const page of contentProcess.pages) {
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, false);
+        pageFound = true;
+        break;
+      }
+    }
+    Assert.equal(pageFound, true);
+
+    info("Check that the profiling logs exist with the expected properties.");
+    Assert.equal(typeof profile.profilingLog, "object");
+    Assert.equal(typeof profile.profilingLog[parentPid], "object");
+    const parentLog = profile.profilingLog[parentPid];
+    Assert.equal(typeof parentLog.profilingLogBegin_TSms, "number");
+    Assert.equal(typeof parentLog.profilingLogEnd_TSms, "number");
+    Assert.equal(typeof parentLog.bufferGlobalController, "object");
+    Assert.equal(
+      typeof parentLog.bufferGlobalController.controllerCreationTime_TSms,
+      "number"
+    );
+
+    Assert.equal(typeof profile.profileGatheringLog, "object");
+    Assert.equal(typeof profile.profileGatheringLog[parentPid], "object");
+    Assert.equal(
+      typeof profile.profileGatheringLog[parentPid]
+        .profileGatheringLogBegin_TSms,
+      "number"
+    );
+    Assert.equal(
+      typeof profile.profileGatheringLog[parentPid].profileGatheringLogEnd_TSms,
+      "number"
+    );
+
+    Assert.equal(typeof contentProcess.profilingLog, "object");
+    Assert.equal(typeof contentProcess.profilingLog[contentPid], "object");
+    Assert.equal(
+      typeof contentProcess.profilingLog[contentPid].profilingLogBegin_TSms,
+      "number"
+    );
+    Assert.equal(
+      typeof contentProcess.profilingLog[contentPid].profilingLogEnd_TSms,
+      "number"
+    );
+
+    Assert.equal(typeof contentProcess.profileGatheringLog, "undefined");
+  } finally {
+    await BrowserTestUtils.closeWindow(win);
+  }
+});
+
+add_task(async function test_profile_fission_private_browsing() {
+  // Requesting the complete log to be able to debug Bug 1586105.
+  SimpleTest.requestCompleteLog();
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still have some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler();
+
+  info("Open a private window with single_frame.html in it.");
+  const win = await BrowserTestUtils.openNewBrowserWindow({
+    private: true,
+    fission: true,
+  });
+
+  try {
+    const url = BASE_URL_HTTPS + "single_frame.html";
+    const contentBrowser = win.gBrowser.selectedBrowser;
+    BrowserTestUtils.loadURI(contentBrowser, url);
+    await BrowserTestUtils.browserLoaded(contentBrowser, false, url);
+
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const activeTabID = contentBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const {
+      contentProcess,
+      contentThread,
+    } = await stopProfilerNowAndGetThreads(contentPid);
+
+    Assert.equal(
+      contentThread.isPrivateBrowsing,
+      true,
+      "The content process has the private browsing flag set to true."
+    );
+
+    Assert.equal(
+      contentThread.userContextId,
+      0,
+      "The content process has the information about the container used for this process"
+    );
+
+    info(
+      "Check if the captured page is the one with correct values we created."
+    );
+
+    let pageFound = false;
+    for (const page of contentProcess.pages) {
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, true);
+        pageFound = true;
+        break;
+      }
+    }
+    Assert.equal(pageFound, true);
+  } finally {
+    await BrowserTestUtils.closeWindow(win);
+  }
+});
diff --git a/tools/profiler/tests/browser/browser_test_profile_multi_frame_page_info.js b/tools/profiler/tests/browser/browser_test_profile_multi_frame_page_info.js
new file mode 100644
index 0000000000..6d48306432
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_profile_multi_frame_page_info.js
@@ -0,0 +1,83 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+if (SpecialPowers.useRemoteSubframes) {
+  // Bug 1586105: these tests could time out in some extremely slow conditions,
+  // when fission is enabled.
+  // Requesting a longer timeout should make it pass.
+  requestLongerTimeout(2);
+}
+
+add_task(async function test_profile_multi_frame_page_info() {
+  // Requesting the complete log to be able to debug Bug 1586105.
+  SimpleTest.requestCompleteLog();
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still have some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with multi frame page."
+  );
+  await startProfiler();
+
+  info("Open a tab with multi_frame.html in it.");
+  // multi_frame.html embeds single_frame.html inside an iframe.
+  const url = BASE_URL + "multi_frame.html";
+  await BrowserTestUtils.withNewTab(url, async function(contentBrowser) {
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const win = Services.wm.getMostRecentWindow("navigator:browser");
+    const activeTabID = win.gBrowser.selectedBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const { contentProcess } = await stopProfilerNowAndGetThreads(contentPid);
+
+    info(
+      "Check if the captured pages are the ones with correct values we created."
+    );
+
+    let parentPage;
+    let foundPage = 0;
+    for (const page of contentProcess.pages) {
+      // Parent page
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, false);
+        parentPage = page;
+        foundPage++;
+        break;
+      }
+    }
+
+    Assert.notEqual(typeof parentPage, "undefined");
+
+    for (const page of contentProcess.pages) {
+      // Child page (iframe)
+      if (page.url == BASE_URL + "single_frame.html") {
+        Assert.equal(page.url, BASE_URL + "single_frame.html");
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        Assert.equal(typeof page.embedderInnerWindowID, "number");
+        Assert.notEqual(typeof parentPage, "undefined");
+        Assert.equal(page.embedderInnerWindowID, parentPage.innerWindowID);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, false);
+        foundPage++;
+        break;
+      }
+    }
+
+    Assert.equal(foundPage, 2);
+  });
+});
diff --git a/tools/profiler/tests/browser/browser_test_profile_single_frame_page_info.js b/tools/profiler/tests/browser/browser_test_profile_single_frame_page_info.js
new file mode 100644
index 0000000000..6f59ae6a7b
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_profile_single_frame_page_info.js
@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+if (SpecialPowers.useRemoteSubframes) {
+  // Bug 1586105: these tests could time out in some extremely slow conditions,
+  // when fission is enabled.
+  // Requesting a longer timeout should make it pass.
+  requestLongerTimeout(2);
+}
+
+add_task(async function test_profile_single_frame_page_info() {
+  // Requesting the complete log to be able to debug Bug 1586105.
+  SimpleTest.requestCompleteLog();
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still have some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler();
+
+  info("Open a tab with single_frame.html in it.");
+  const url = BASE_URL + "single_frame.html";
+  await BrowserTestUtils.withNewTab(url, async function(contentBrowser) {
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const win = Services.wm.getMostRecentWindow("navigator:browser");
+    const activeTabID = win.gBrowser.selectedBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const { contentProcess } = await stopProfilerNowAndGetThreads(contentPid);
+
+    info(
+      "Check if the captured page is the one with correct values we created."
+    );
+
+    let pageFound = false;
+    for (const page of contentProcess.pages) {
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, false);
+        pageFound = true;
+        break;
+      }
+    }
+    Assert.equal(pageFound, true);
+  });
+});
+
+add_task(async function test_profile_private_browsing() {
+  // Requesting the complete log to be able to debug Bug 1586105.
+  SimpleTest.requestCompleteLog();
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still have some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler();
+
+  info("Open a private window with single_frame.html in it.");
+  const win = await BrowserTestUtils.openNewBrowserWindow({
+    fission: false,
+    private: true,
+  });
+
+  try {
+    const url = BASE_URL_HTTPS + "single_frame.html";
+    const contentBrowser = win.gBrowser.selectedBrowser;
+    BrowserTestUtils.loadURI(contentBrowser, url);
+    await BrowserTestUtils.browserLoaded(contentBrowser, false, url);
+
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const activeTabID = contentBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const {
+      contentProcess,
+      contentThread,
+    } = await stopProfilerNowAndGetThreads(contentPid);
+
+    // This information is available with fission only.
+    Assert.equal(
+      contentThread.isPrivateBrowsing,
+      undefined,
+      "The content process has no private browsing flag."
+    );
+
+    Assert.equal(
+      contentThread.userContextId,
+      undefined,
+      "The content process has no information about the container used for this process."
+    );
+
+    info(
+      "Check if the captured page is the one with correct values we created."
+    );
+
+    let pageFound = false;
+    for (const page of contentProcess.pages) {
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        Assert.equal(typeof page.isPrivateBrowsing, "boolean");
+        Assert.equal(page.isPrivateBrowsing, true);
+        pageFound = true;
+        break;
+      }
+    }
+    Assert.equal(pageFound, true);
+  } finally {
+    await BrowserTestUtils.closeWindow(win);
+  }
+});
diff --git a/tools/profiler/tests/browser/browser_test_profile_slow_capture.js b/tools/profiler/tests/browser/browser_test_profile_slow_capture.js
new file mode 100644
index 0000000000..83795aaf38
--- /dev/null
+++ b/tools/profiler/tests/browser/browser_test_profile_slow_capture.js
@@ -0,0 +1,104 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async function browser_test_profile_slow_capture() {
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler({ threads: ["GeckoMain", "test-debug-child-slow-json"] });
+
+  info("Open a tab with single_frame.html in it.");
+  const url = BASE_URL + "single_frame.html";
+  await BrowserTestUtils.withNewTab(url, async function(contentBrowser) {
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    // Getting the active Browser ID to assert the page info tabID later.
+    const win = Services.wm.getMostRecentWindow("navigator:browser");
+    const activeTabID = win.gBrowser.selectedBrowser.browsingContext.browserId;
+
+    info("Capture the profile data.");
+    const profile = await waitSamplingAndStopAndGetProfile();
+
+    let pageFound = false;
+    // We need to find the correct content process for that tab.
+    let contentProcess = profile.processes.find(
+      p => p.threads[0].pid == contentPid
+    );
+
+    if (!contentProcess) {
+      throw new Error(
+        `Could not find the content process with given pid: ${contentPid}`
+      );
+    }
+
+    info(
+      "Check if the captured page is the one with correct values we created."
+    );
+
+    for (const page of contentProcess.pages) {
+      if (page.url == url) {
+        Assert.equal(page.url, url);
+        Assert.equal(typeof page.tabID, "number");
+        Assert.equal(page.tabID, activeTabID);
+        Assert.equal(typeof page.innerWindowID, "number");
+        // Top level document will have no embedder.
+        Assert.equal(page.embedderInnerWindowID, 0);
+        pageFound = true;
+        break;
+      }
+    }
+    Assert.equal(pageFound, true);
+
+    info("Flush slow processes with a quick profile.");
+    await startProfiler();
+    for (let i = 0; i < 10; ++i) {
+      await Services.profiler.waitOnePeriodicSampling();
+    }
+    await stopNowAndGetProfile();
+  });
+});
+
+add_task(async function browser_test_profile_very_slow_capture() {
+  Assert.ok(!Services.profiler.IsActive());
+  info("Clear the previous pages just in case we still some open tabs.");
+  await Services.profiler.ClearAllPages();
+
+  info(
+    "Start the profiler to test the page information with single frame page."
+  );
+  await startProfiler({
+    threads: ["GeckoMain", "test-debug-child-very-slow-json"],
+  });
+
+  info("Open a tab with single_frame.html in it.");
+  const url = BASE_URL + "single_frame.html";
+  await BrowserTestUtils.withNewTab(url, async function(contentBrowser) {
+    const contentPid = await SpecialPowers.spawn(contentBrowser, [], () => {
+      return Services.appinfo.processID;
+    });
+
+    info("Capture the profile data.");
+    const profile = await waitSamplingAndStopAndGetProfile();
+
+    info("Check that the content process is missing.");
+
+    let contentProcessIndex = profile.processes.findIndex(
+      p => p.threads[0].pid == contentPid
+    );
+    Assert.equal(contentProcessIndex, -1);
+
+    info("Flush slow processes with a quick profile.");
+    await startProfiler();
+    for (let i = 0; i < 10; ++i) {
+      await Services.profiler.waitOnePeriodicSampling();
+    }
+    await stopNowAndGetProfile();
+  });
+});
diff --git a/tools/profiler/tests/browser/do_work_500ms.html b/tools/profiler/tests/browser/do_work_500ms.html
new file mode 100644
index 0000000000..9713a80671
--- /dev/null
+++ b/tools/profiler/tests/browser/do_work_500ms.html
@@ -0,0 +1,41 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Do some work for 500ms</title>
+  <script>
+    const milliseconds = 500;
+    const millisecondsPerBatch = 10;
+    const end = Date.now() + milliseconds;
+    window.total = 0;
+    let i = 0;
+
+    /**
+     * Do work for a set number of milliseconds, but only do the work in batches
+     * so the browser does not get unresponsive.
+     */
+    function doWork() {
+      const batchEnd = Date.now() + millisecondsPerBatch;
+      // Do some work for a set amount of time.
+      while (Date.now() < end) {
+        // Do some kind of work that is non-deterministic to guard against optimizations.
+        window.total += Math.random();
+        i++;
+
+        // Check if a batch is done yet.
+        if (Date.now() > batchEnd) {
+          // Defer the rest of the work into a micro task. Keep on doing this until
+          // the total milliseconds have elapsed.
+          setTimeout(doWork, 0);
+          return;
+        }
+      }
+    }
+
+    doWork();
+  </script>
+</head>
+<body>
+  Do some work for 500ms.
+</body>
+</html>
diff --git a/tools/profiler/tests/browser/firefox-logo-nightly.svg b/tools/profiler/tests/browser/firefox-logo-nightly.svg
new file mode 100644
index 0000000000..f1af370d87
--- /dev/null
+++ b/tools/profiler/tests/browser/firefox-logo-nightly.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 953.37 984"><defs><linearGradient id="linear-gradient" x1="-14706.28" y1="9250.14" x2="-14443.04" y2="9250.14" gradientTransform="matrix(0.76, 0.03, 0.05, -1.12, 11485.47, 11148)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.1" stop-color="#0092f8"/><stop offset="0.31" stop-color="#00abeb"/><stop offset="0.52" stop-color="#00bee1"/><stop offset="0.75" stop-color="#00c8dc"/><stop offset="1" stop-color="#00ccda"/></linearGradient><radialGradient id="radial-gradient" cx="-7588.66" cy="8866.53" r="791.23" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0.02" stop-color="#005fe7"/><stop offset="0.18" stop-color="#0042b4"/><stop offset="0.32" stop-color="#002989"/><stop offset="0.4" stop-color="#002079"/><stop offset="0.47" stop-color="#131d78"/><stop offset="0.66" stop-color="#3b1676"/><stop offset="0.75" stop-color="#4a1475"/></radialGradient><linearGradient id="linear-gradient-2" x1="539.64" y1="254.8" x2="348.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 1, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#000f43" stop-opacity="0.4"/><stop offset="0.48" stop-color="#001962" stop-opacity="0.17"/><stop offset="1" stop-color="#002079" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-3" x1="540.64" y1="254.8" x2="349.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" xlink:href="#linear-gradient-2"/><linearGradient id="linear-gradient-4" x1="-8367.12" y1="7348.87" x2="-8482.36" y2="7357.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#812cc9"/><stop offset="1" stop-color="#005fe7"/></linearGradient><linearGradient id="linear-gradient-5" x1="-8449.89" y1="7496.97" x2="-8341.94" y2="7609.09" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.05" stop-color="#005fe7"/><stop offset="0.18" stop-color="#065de6"/><stop offset="0.35" stop-color="#1856e1"/><stop offset="0.56" stop-color="#354adb"/><stop offset="0.78" stop-color="#5d3ad1"/><stop offset="0.95" stop-color="#812cc9"/></linearGradient><linearGradient id="linear-gradient-6" x1="-8653.41" y1="7245.3" x2="-8422.52" y2="7244.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#002079"/><stop offset="0.99" stop-color="#a238ff"/></linearGradient><radialGradient id="radial-gradient-2" cx="644.11" cy="599.83" fx="785.0454815336918" fy="470.6889181532662" r="793.95" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0.2" stop-color="#00fdff"/><stop offset="0.26" stop-color="#0af1ff"/><stop offset="0.37" stop-color="#23d2ff"/><stop offset="0.52" stop-color="#4da0ff"/><stop offset="0.69" stop-color="#855bff"/><stop offset="0.77" stop-color="#a238ff"/><stop offset="0.81" stop-color="#a738fd"/><stop offset="0.86" stop-color="#b539f9"/><stop offset="0.9" stop-color="#cd39f1"/><stop offset="0.96" stop-color="#ee3ae6"/><stop offset="0.98" stop-color="#ff3be0"/></radialGradient><linearGradient id="linear-gradient-7" x1="-7458.97" y1="9093.17" x2="-7531.06" y2="8282.84" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00"/><stop offset="0.1" stop-color="#00e244"/><stop offset="0.22" stop-color="#00d694"/><stop offset="0.31" stop-color="#00cfc7"/><stop offset="0.35" stop-color="#00ccda"/><stop offset="0.42" stop-color="#0bc2dd" stop-opacity="0.92"/><stop offset="0.57" stop-color="#29a7e4" stop-opacity="0.72"/><stop offset="0.77" stop-color="#597df0" stop-opacity="0.4"/><stop offset="1" stop-color="#9448ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-8" x1="-8926.61" y1="7680.53" x2="-8790.14" y2="7680.53" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#005fe7"/><stop offset="0.46" stop-color="#0071f3" stop-opacity="0.51"/><stop offset="0.83" stop-color="#007efc" stop-opacity="0.14"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><radialGradient id="radial-gradient-3" cx="-8914.62" cy="7721.05" r="165.97" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.63" stop-color="#ffe302" stop-opacity="0"/><stop offset="0.67" stop-color="#ffe302" stop-opacity="0.05"/><stop offset="0.75" stop-color="#ffe302" stop-opacity="0.19"/><stop offset="0.86" stop-color="#ffe302" stop-opacity="0.4"/><stop offset="0.99" stop-color="#ffe302" stop-opacity="0.7"/></radialGradient><linearGradient id="linear-gradient-9" x1="214.02" y1="2032.47" x2="96.19" y2="2284.31" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, -250.1, 2306.29)" gradientUnits="userSpaceOnUse"><stop offset="0.19" stop-color="#4a1475" stop-opacity="0.5"/><stop offset="0.62" stop-color="#2277ac" stop-opacity="0.23"/><stop offset="0.94" stop-color="#00ccda" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-10" x1="-38.44" y1="278.18" x2="55.67" y2="171.29" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0.01" stop-color="#002079" stop-opacity="0.5"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-11" x1="142.45" y1="96.25" x2="142.5" y2="149.68" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#4a1475" stop-opacity="0.9"/><stop offset="0.18" stop-color="#6720a2" stop-opacity="0.6"/><stop offset="0.38" stop-color="#812acb" stop-opacity="0.34"/><stop offset="0.57" stop-color="#9332e8" stop-opacity="0.15"/><stop offset="0.76" stop-color="#9e36f9" stop-opacity="0.04"/><stop offset="0.93" stop-color="#a238ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-12" x1="620.52" y1="947.88" x2="926.18" y2="264.39" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00" stop-opacity="0"/><stop offset="0.28" stop-color="#00dc6d" stop-opacity="0.5"/><stop offset="0.5" stop-color="#00d1bb" stop-opacity="0.86"/><stop offset="0.6" stop-color="#00ccda"/><stop offset="0.68" stop-color="#04c9db"/><stop offset="0.75" stop-color="#0fc1df"/><stop offset="0.83" stop-color="#23b2e6"/><stop offset="0.9" stop-color="#3e9ef0"/><stop offset="0.98" stop-color="#6184fc"/><stop offset="0.99" stop-color="#6680fe"/></linearGradient><linearGradient id="linear-gradient-13" x1="680.88" y1="554.79" x2="536.1" y2="166.04" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.04" stop-color="#0083ff" stop-opacity="0.92"/><stop offset="0.14" stop-color="#0083ff" stop-opacity="0.71"/><stop offset="0.26" stop-color="#0083ff" stop-opacity="0.52"/><stop offset="0.37" stop-color="#0083ff" stop-opacity="0.36"/><stop offset="0.49" stop-color="#0083ff" stop-opacity="0.23"/><stop offset="0.61" stop-color="#0083ff" stop-opacity="0.13"/><stop offset="0.73" stop-color="#0083ff" stop-opacity="0.06"/><stop offset="0.86" stop-color="#0083ff" stop-opacity="0.01"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient></defs><title>firefox-logo-nightly</title><g id="Layer_2" data-name="Layer 2"><g id="Layer_1-2" data-name="Layer 1"><g id="Layer_2-2" data-name="Layer 2"><g id="Firefox"><path d="M770.28,91.56c-23.95,27.88-35.1,90.64-10.82,154.26s61.5,49.8,84.7,114.67c30.62,85.6,16.37,200.59,16.37,200.59s36.81,106.61,62.47-6.63C979.79,341.74,770.28,143.94,770.28,91.56Z" style="fill:url(#linear-gradient)"/><path id="_Path_" data-name=" Path " d="M476.92,972.83c245.24,0,443.9-199.74,443.9-446s-198.66-446-443.66-446S33.5,280.51,33.5,526.8C33,773.33,231.92,972.83,476.92,972.83Z" style="fill:url(#radial-gradient)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-2)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-3)"/><path d="M711.1,866.71c162.87-18.86,235-186.7,142.38-190C769.85,674,634,875.61,711.1,866.71Z" style="fill:url(#linear-gradient-4)"/><path d="M865.21,642.42C977.26,577.21,948,436.34,948,436.34s-43.25,50.24-72.62,130.32C846.4,646,797.84,681.81,865.21,642.42Z" style="fill:url(#linear-gradient-5)"/><path d="M509.47,950.06C665.7,999.91,800,876.84,717.21,835.74,642,798.68,435.32,926.49,509.47,950.06Z" style="fill:url(#linear-gradient-6)"/><path d="M638.58,21.42l.53-.57A1.7,1.7,0,0,0,638.58,21.42ZM876.85,702.23c3.8-5.36,8.94-22.53,13.48-30.21,27.58-44.52,27.78-80,27.78-80.84,16.66-83.22,15.15-117.2,4.9-180-8.25-50.6-44.32-123.09-75.57-158-32.2-36-9.51-24.25-40.69-50.52-27.33-30.29-53.82-60.29-68.25-72.36C634.22,43.09,636.57,24.58,638.58,21.42c-.34.37-.84.92-1.47,1.64C635.87,18.14,635,14,635,14s-57,57-69,152c-7.83,62,15.38,126.68,49,168a381.62,381.62,0,0,0,59,58h0c25.4,36.48,39.38,81.49,39.38,129.91,0,121.24-98.34,219.53-219.65,219.53a220.14,220.14,0,0,1-49.13-5.52c-57.24-10.92-90.3-39.8-106.78-59.41-9.45-11.23-13.46-19.42-13.46-19.42,51.28,18.37,108,14.53,142.47-4.52,34.75-19.26,55.77-33.55,72.84-27.92,16.82,5.61,30.21-10.67,18.2-27.54-11.77-16.85-42.4-41-87.88-34.29-34.79,5.07-66.66,29.76-112.24,5.84a97.34,97.34,0,0,1-8.55-5c-3-1.77,9.77,2.69,6.79.68-8.87-4.32-24.57-13.73-28.64-17.07-.68-.56,6.88,2.16,6.2,1.6-42.62-31.45-37.3-52.69-36-66,1.07-10.66,8.81-24.32,21.86-29.86,6.3,3.08,10.23,5.43,10.23,5.43s-2.69-4.92-4.14-7.51c.51-.19,1-.15,1.5-.34,5.16,2.23,16.58,8,22.59,11.57,7.83,4.95,10.32,9.36,10.32,9.36s2.06-1,.54-5.33c-.56-1.77-2.93-7.39-10.68-13.07h.48a91.65,91.65,0,0,1,13.13,8.17c2.19-7.12,6.12-14.56,5.25-27.86-.53-9.35-.28-11.78-2.12-15.39-1.65-3.1.92-4.31,3.78-1.09a29.73,29.73,0,0,0-2.44-7.34v-.24c3.57-11.14,75.53-40.12,80.77-43.51a70.24,70.24,0,0,0,21.17-20.63c4-5.72,7-13.73,7.75-25.89.25-5.48-1.44-9.82-20.5-14-11.44-2.49-29.14-4.91-56.43-7.47-19.9-1.76-31.58-14.68-38.21-26.6-1.21-2.57-2.45-4.9-3.68-7.22a53.41,53.41,0,0,1-2.83-8.36,158.47,158.47,0,0,1,61.28-76.06c1.6-1.31-6.4.33-4.8-1,1.87-1.52,14.06-5.93,16.37-6.92,2.81-1.19-12-6.84-25.16-5.47-13.36,1.35-16.19,2.78-23.32,5.49,3-2.64,12.37-6.1,10.16-6.08-14.4,2-32.3,9.48-47.6,18a9.72,9.72,0,0,1,.92-4.31c-7.13,2.71-24.64,13.67-29.73,23a39.79,39.79,0,0,0,.29-5.35,88.55,88.55,0,0,0-14.6,13.7l-.27.22C258.14,196,221.75,195,191,201.72c-6.74-6.06-17.57-15.23-32.89-45.4-1-1.82-1.6,3.75-2.4,2-6-13.81-9.55-36.44-9-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.87-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.37,12.62-1.38,4-3.32,6.27-4.56,11.29l-.29.46c-.1-1.48.37-6.08,0-5.14A235.4,235.4,0,0,0,95.34,186c-5.49,18-11.88,42.61-12.89,74.57-.24,2.42,0,5.14-.25,7.32-13,14.83-21.86,27.39-25.2,33.91-16.81,26-35.33,66.44-53.29,130.46a319.35,319.35,0,0,1,28.54-50C17.32,416.25,2.89,469.62,0,551.8a436.92,436.92,0,0,1,13.87-50.24C11.29,556.36,17.68,624.3,52.32,701c20.57,45,67.92,136.6,183.62,208h0s39.36,29.3,107,51.26c5,1.81,10.06,3.6,15.23,5.33q-2.43-1-4.71-2A484.9,484.9,0,0,0,492.27,984c175.18.15,226.85-70.2,226.85-70.2l-.51.38q3.71-3.49,7.14-7.26c-27.64,26.08-90.75,27.84-114.3,26,40.22-11.81,66.69-21.81,118.17-41.52q9-3.36,18.48-7.64l2-.94c1.25-.58,2.49-1.13,3.75-1.74a349.3,349.3,0,0,0,70.26-44c51.7-41.3,63-81.56,68.83-108.1-.82,2.54-3.37,8.47-5.17,12.32-13.31,28.48-42.84,46-74.91,61a689.05,689.05,0,0,0,42.38-62.44C865.77,729.39,869,713.15,876.85,702.23Z" style="fill:url(#radial-gradient-2)"/><path d="M813.92,801c21.08-23.24,40-49.82,54.35-80,36.9-77.58,94-206.58,49-341.31C881.77,273.22,833,215,771.11,158.12,670.56,65.76,642.48,24.52,642.48,0c0,0-116.09,129.41-65.74,264.38s153.46,130,221.68,270.87c80.27,165.74-64.95,346.61-185,397.24,7.35-1.63,267-60.38,280.61-208.88C893.68,726.34,887.83,767.41,813.92,801Z" style="fill:url(#linear-gradient-7)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="fill:url(#linear-gradient-8)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="opacity:0.5;isolation:isolate;fill:url(#radial-gradient-3)"/><path d="M158.31,156.47c-1-1.82-1.6,3.75-2.4,2-6-13.81-9.58-36.2-8.72-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.86-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.35,12.38-1.65,4.24-3.35,6.52-4.61,11.77-.39,1.43.39-6.32,0-5.38C84.72,201.68,80.19,271,82.69,268,133.17,214.14,191,201.36,191,201.36c-6.15-4.53-19.53-17.63-32.7-44.89Z" style="fill:url(#linear-gradient-9)"/><path d="M349.84,720.1c-69.72-29.77-149-71.75-146-167.14C207.92,427.35,321,452.18,321,452.18c-4.27,1-15.68,9.16-19.72,17.82-4.27,10.83-12.07,35.28,11.55,60.9,37.09,40.19-76.2,95.36,98.66,199.57,4.41,2.4-41-1.43-61.64-10.36Z" style="fill:url(#linear-gradient-10)"/><path d="M325.07,657.5c49.44,17.21,107,14.19,141.52-4.86,23.09-12.85,52.7-33.43,70.92-28.35-15.78-6.24-27.73-9.15-42.1-9.86-2.45,0-5.38,0-8-.32a136,136,0,0,0-15.76.86c-8.9.82-18.77,6.43-27.74,5.53-.48,0,8.7-3.77,8-3.61-4.75,1-9.92,1.21-15.37,1.88-3.47.39-6.45.82-9.89,1-103,8.73-190-55.81-190-55.81-7.41,25,33.17,74.3,88.52,93.57Z" style="opacity:0.5;isolation:isolate;fill:url(#linear-gradient-11)"/><path d="M813.74,801.65c104.16-102.27,156.86-226.58,134.58-366,0,0,8.9,71.5-24.85,144.63,16.21-71.39,18.1-160.11-25-252C841,205.64,746.45,141.11,710.35,114.19,655.66,73.4,633,31.87,632.57,23.3c-16.34,33.48-65.77,148.2-5.31,247,56.64,92.56,145.86,120,208.33,205C950.67,631.67,813.74,801.65,813.74,801.65Z" style="fill:url(#linear-gradient-12)"/><path d="M798.81,535.55C762.41,460.35,717,427.55,674,392c5,7,6.23,9.47,9,14,37.83,40.32,93.61,138.66,53.11,262.11C659.88,900.48,355,791.06,323,760.32,335.93,894.81,561,959.16,707.6,872,791,793,858.47,658.79,798.81,535.55Z" style="fill:url(#linear-gradient-13)"/></g></g></g></g></svg>
\ No newline at end of file
diff --git a/tools/profiler/tests/browser/head.js b/tools/profiler/tests/browser/head.js
new file mode 100644
index 0000000000..ef0e3128c0
--- /dev/null
+++ b/tools/profiler/tests/browser/head.js
@@ -0,0 +1,159 @@
+/* import-globals-from ../shared-head.js */
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/tools/profiler/tests/browser/shared-head.js",
+  this
+);
+
+const BASE_URL = "http://example.com/browser/tools/profiler/tests/browser/";
+const BASE_URL_HTTPS =
+  "https://example.com/browser/tools/profiler/tests/browser/";
+
+registerCleanupFunction(async () => {
+  if (Services.profiler.IsActive()) {
+    info(
+      "The profiler was found to still be running at the end of the test, which means that some error likely occured. Let's stop it to prevent issues with following tests!"
+    );
+    await Services.profiler.StopProfiler();
+  }
+});
+
+/**
+ * This is a helper function that will stop the profiler and returns the main
+ * threads for the parent process and the content process with PID contentPid.
+ * This happens immediately, without waiting for any sampling to happen or
+ * finish. Use waitSamplingAndStopProfilerAndGetThreads below instead to wait
+ * for samples before stopping.
+ * This returns also the full profile in case the caller wants more information.
+ *
+ * @param {number} contentPid
+ * @returns {Promise<{profile, parentThread, contentProcess, contentThread}>}
+ */
+async function stopProfilerNowAndGetThreads(contentPid) {
+  const profile = await stopNowAndGetProfile();
+
+  const parentThread = profile.threads[0];
+  const contentProcess = profile.processes.find(
+    p => p.threads[0].pid == contentPid
+  );
+  if (!contentProcess) {
+    throw new Error(
+      `Could not find the content process with given pid: ${contentPid}`
+    );
+  }
+
+  if (!parentThread) {
+    throw new Error("The parent thread was not found in the profile.");
+  }
+
+  const contentThread = contentProcess.threads[0];
+  if (!contentThread) {
+    throw new Error("The content thread was not found in the profile.");
+  }
+
+  return { profile, parentThread, contentProcess, contentThread };
+}
+
+/**
+ * This is a helper function that will stop the profiler and returns the main
+ * threads for the parent process and the content process with PID contentPid.
+ * As opposed to stopProfilerNowAndGetThreads (with "Now") above, the profiler
+ * in that PID will not stop until there is at least one periodic sample taken.
+ *
+ * @param {number} contentPid
+ * @returns {Promise<{profile, parentThread, contentProcess, contentThread}>}
+ */
+async function waitSamplingAndStopProfilerAndGetThreads(contentPid) {
+  await Services.profiler.waitOnePeriodicSampling();
+
+  return stopProfilerNowAndGetThreads(contentPid);
+}
+
+/** This tries to find the service worker thread by targeting a very specific
+ * UserTiming marker. Indeed we use performance.mark to add this marker from the
+ * service worker's events.
+ * Then from this thread we get its parent thread. Indeed the parent thread is
+ * where all network stuff happens, so this is useful for network marker tests.
+ *
+ * @param {Object} profile
+ * @returns {{ serviceWorkerThread: Object, serviceWorkerParentThread: Object }} the found threads
+ */
+function findServiceWorkerThreads(profile) {
+  const allThreads = [
+    profile.threads,
+    ...profile.processes.map(process => process.threads),
+  ].flat();
+
+  const serviceWorkerThread = allThreads.find(
+    ({ processType, markers }) =>
+      processType === "tab" &&
+      markers.data.some(markerTuple => {
+        const data = markerTuple[markers.schema.data];
+        return (
+          data &&
+          data.type === "UserTiming" &&
+          data.name === "__serviceworker_event"
+        );
+      })
+  );
+
+  if (!serviceWorkerThread) {
+    info(
+      "We couldn't find a service worker thread. Here are all the threads in this profile:"
+    );
+    allThreads.forEach(logInformationForThread.bind(null, ""));
+    return null;
+  }
+
+  const serviceWorkerParentThread = allThreads.find(
+    ({ name, pid }) => pid === serviceWorkerThread.pid && name === "GeckoMain"
+  );
+
+  if (!serviceWorkerParentThread) {
+    info(
+      `We couldn't find a parent thread for the service worker thread (pid: ${serviceWorkerThread.pid}, tid: ${serviceWorkerThread.tid}).`
+    );
+    info("Here are all the threads in this profile:");
+    allThreads.forEach(logInformationForThread.bind(null, ""));
+
+    // Let's write the profile on disk if MOZ_UPLOAD_DIR is present
+    const path = Services.env.get("MOZ_UPLOAD_DIR");
+    if (path) {
+      const profileName = `profile_${Date.now()}.json`;
+      const profilePath = PathUtils.join(path, profileName);
+      info(
+        `We wrote down the profile on disk as an artifact, with name ${profileName}.`
+      );
+      // This function returns a Promise, but we're not waiting on it because
+      // we're in a synchronous function. Hopefully writing will be finished
+      // when the process ends.
+      IOUtils.writeJSON(profilePath, profile).catch(err =>
+        console.error("An error happened when writing the profile on disk", err)
+      );
+    }
+    throw new Error(
+      "We couldn't find a parent thread for the service worker thread. Please read logs to find more information."
+    );
+  }
+
+  return { serviceWorkerThread, serviceWorkerParentThread };
+}
+
+/**
+ * This logs some basic information about the passed thread.
+ *
+ * @param {string} prefix
+ * @param {Object} thread
+ */
+function logInformationForThread(prefix, thread) {
+  if (!thread) {
+    info(prefix + ": thread is null or undefined.");
+    return;
+  }
+
+  const { name, pid, tid, processName, processType } = thread;
+  info(
+    `${prefix}: ` +
+      `name(${name}) pid(${pid}) tid(${tid}) processName(${processName}) processType(${processType})`
+  );
+}
diff --git a/tools/profiler/tests/browser/multi_frame.html b/tools/profiler/tests/browser/multi_frame.html
new file mode 100644
index 0000000000..b2efcedd50
--- /dev/null
+++ b/tools/profiler/tests/browser/multi_frame.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Multi Frame</title>
+</head>
+<body>
+  Multi Frame
+  <iframe src="single_frame.html"></iframe>
+</body>
+</html>
diff --git a/tools/profiler/tests/browser/page_with_resources.html b/tools/profiler/tests/browser/page_with_resources.html
new file mode 100644
index 0000000000..9d2bb8f218
--- /dev/null
+++ b/tools/profiler/tests/browser/page_with_resources.html
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+    Testing
+    <img src='firefox-logo-nightly.svg' width="24"/>
+    <img src='redirect.sjs?firefox-logo-nightly.svg' width="24"/>
+  </body>
+</html>
diff --git a/tools/profiler/tests/browser/redirect.sjs b/tools/profiler/tests/browser/redirect.sjs
new file mode 100644
index 0000000000..2a325c3d0b
--- /dev/null
+++ b/tools/profiler/tests/browser/redirect.sjs
@@ -0,0 +1,8 @@
+function handleRequest(request, response) {
+  response.setStatusLine(request.httpVersion, 301, "Moved Permanently");
+  response.setHeader(
+    "Location",
+    decodeURIComponent(request.queryString),
+    false
+  );
+}
diff --git a/tools/profiler/tests/browser/serviceworkers/firefox-logo-nightly.svg b/tools/profiler/tests/browser/serviceworkers/firefox-logo-nightly.svg
new file mode 100644
index 0000000000..f1af370d87
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/firefox-logo-nightly.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 953.37 984"><defs><linearGradient id="linear-gradient" x1="-14706.28" y1="9250.14" x2="-14443.04" y2="9250.14" gradientTransform="matrix(0.76, 0.03, 0.05, -1.12, 11485.47, 11148)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.1" stop-color="#0092f8"/><stop offset="0.31" stop-color="#00abeb"/><stop offset="0.52" stop-color="#00bee1"/><stop offset="0.75" stop-color="#00c8dc"/><stop offset="1" stop-color="#00ccda"/></linearGradient><radialGradient id="radial-gradient" cx="-7588.66" cy="8866.53" r="791.23" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0.02" stop-color="#005fe7"/><stop offset="0.18" stop-color="#0042b4"/><stop offset="0.32" stop-color="#002989"/><stop offset="0.4" stop-color="#002079"/><stop offset="0.47" stop-color="#131d78"/><stop offset="0.66" stop-color="#3b1676"/><stop offset="0.75" stop-color="#4a1475"/></radialGradient><linearGradient id="linear-gradient-2" x1="539.64" y1="254.8" x2="348.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 1, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#000f43" stop-opacity="0.4"/><stop offset="0.48" stop-color="#001962" stop-opacity="0.17"/><stop offset="1" stop-color="#002079" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-3" x1="540.64" y1="254.8" x2="349.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" xlink:href="#linear-gradient-2"/><linearGradient id="linear-gradient-4" x1="-8367.12" y1="7348.87" x2="-8482.36" y2="7357.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#812cc9"/><stop offset="1" stop-color="#005fe7"/></linearGradient><linearGradient id="linear-gradient-5" x1="-8449.89" y1="7496.97" x2="-8341.94" y2="7609.09" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.05" stop-color="#005fe7"/><stop offset="0.18" stop-color="#065de6"/><stop offset="0.35" stop-color="#1856e1"/><stop offset="0.56" stop-color="#354adb"/><stop offset="0.78" stop-color="#5d3ad1"/><stop offset="0.95" stop-color="#812cc9"/></linearGradient><linearGradient id="linear-gradient-6" x1="-8653.41" y1="7245.3" x2="-8422.52" y2="7244.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#002079"/><stop offset="0.99" stop-color="#a238ff"/></linearGradient><radialGradient id="radial-gradient-2" cx="644.11" cy="599.83" fx="785.0454815336918" fy="470.6889181532662" r="793.95" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0.2" stop-color="#00fdff"/><stop offset="0.26" stop-color="#0af1ff"/><stop offset="0.37" stop-color="#23d2ff"/><stop offset="0.52" stop-color="#4da0ff"/><stop offset="0.69" stop-color="#855bff"/><stop offset="0.77" stop-color="#a238ff"/><stop offset="0.81" stop-color="#a738fd"/><stop offset="0.86" stop-color="#b539f9"/><stop offset="0.9" stop-color="#cd39f1"/><stop offset="0.96" stop-color="#ee3ae6"/><stop offset="0.98" stop-color="#ff3be0"/></radialGradient><linearGradient id="linear-gradient-7" x1="-7458.97" y1="9093.17" x2="-7531.06" y2="8282.84" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00"/><stop offset="0.1" stop-color="#00e244"/><stop offset="0.22" stop-color="#00d694"/><stop offset="0.31" stop-color="#00cfc7"/><stop offset="0.35" stop-color="#00ccda"/><stop offset="0.42" stop-color="#0bc2dd" stop-opacity="0.92"/><stop offset="0.57" stop-color="#29a7e4" stop-opacity="0.72"/><stop offset="0.77" stop-color="#597df0" stop-opacity="0.4"/><stop offset="1" stop-color="#9448ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-8" x1="-8926.61" y1="7680.53" x2="-8790.14" y2="7680.53" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#005fe7"/><stop offset="0.46" stop-color="#0071f3" stop-opacity="0.51"/><stop offset="0.83" stop-color="#007efc" stop-opacity="0.14"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><radialGradient id="radial-gradient-3" cx="-8914.62" cy="7721.05" r="165.97" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.63" stop-color="#ffe302" stop-opacity="0"/><stop offset="0.67" stop-color="#ffe302" stop-opacity="0.05"/><stop offset="0.75" stop-color="#ffe302" stop-opacity="0.19"/><stop offset="0.86" stop-color="#ffe302" stop-opacity="0.4"/><stop offset="0.99" stop-color="#ffe302" stop-opacity="0.7"/></radialGradient><linearGradient id="linear-gradient-9" x1="214.02" y1="2032.47" x2="96.19" y2="2284.31" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, -250.1, 2306.29)" gradientUnits="userSpaceOnUse"><stop offset="0.19" stop-color="#4a1475" stop-opacity="0.5"/><stop offset="0.62" stop-color="#2277ac" stop-opacity="0.23"/><stop offset="0.94" stop-color="#00ccda" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-10" x1="-38.44" y1="278.18" x2="55.67" y2="171.29" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0.01" stop-color="#002079" stop-opacity="0.5"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-11" x1="142.45" y1="96.25" x2="142.5" y2="149.68" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#4a1475" stop-opacity="0.9"/><stop offset="0.18" stop-color="#6720a2" stop-opacity="0.6"/><stop offset="0.38" stop-color="#812acb" stop-opacity="0.34"/><stop offset="0.57" stop-color="#9332e8" stop-opacity="0.15"/><stop offset="0.76" stop-color="#9e36f9" stop-opacity="0.04"/><stop offset="0.93" stop-color="#a238ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-12" x1="620.52" y1="947.88" x2="926.18" y2="264.39" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00" stop-opacity="0"/><stop offset="0.28" stop-color="#00dc6d" stop-opacity="0.5"/><stop offset="0.5" stop-color="#00d1bb" stop-opacity="0.86"/><stop offset="0.6" stop-color="#00ccda"/><stop offset="0.68" stop-color="#04c9db"/><stop offset="0.75" stop-color="#0fc1df"/><stop offset="0.83" stop-color="#23b2e6"/><stop offset="0.9" stop-color="#3e9ef0"/><stop offset="0.98" stop-color="#6184fc"/><stop offset="0.99" stop-color="#6680fe"/></linearGradient><linearGradient id="linear-gradient-13" x1="680.88" y1="554.79" x2="536.1" y2="166.04" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.04" stop-color="#0083ff" stop-opacity="0.92"/><stop offset="0.14" stop-color="#0083ff" stop-opacity="0.71"/><stop offset="0.26" stop-color="#0083ff" stop-opacity="0.52"/><stop offset="0.37" stop-color="#0083ff" stop-opacity="0.36"/><stop offset="0.49" stop-color="#0083ff" stop-opacity="0.23"/><stop offset="0.61" stop-color="#0083ff" stop-opacity="0.13"/><stop offset="0.73" stop-color="#0083ff" stop-opacity="0.06"/><stop offset="0.86" stop-color="#0083ff" stop-opacity="0.01"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient></defs><title>firefox-logo-nightly</title><g id="Layer_2" data-name="Layer 2"><g id="Layer_1-2" data-name="Layer 1"><g id="Layer_2-2" data-name="Layer 2"><g id="Firefox"><path d="M770.28,91.56c-23.95,27.88-35.1,90.64-10.82,154.26s61.5,49.8,84.7,114.67c30.62,85.6,16.37,200.59,16.37,200.59s36.81,106.61,62.47-6.63C979.79,341.74,770.28,143.94,770.28,91.56Z" style="fill:url(#linear-gradient)"/><path id="_Path_" data-name=" Path " d="M476.92,972.83c245.24,0,443.9-199.74,443.9-446s-198.66-446-443.66-446S33.5,280.51,33.5,526.8C33,773.33,231.92,972.83,476.92,972.83Z" style="fill:url(#radial-gradient)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-2)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-3)"/><path d="M711.1,866.71c162.87-18.86,235-186.7,142.38-190C769.85,674,634,875.61,711.1,866.71Z" style="fill:url(#linear-gradient-4)"/><path d="M865.21,642.42C977.26,577.21,948,436.34,948,436.34s-43.25,50.24-72.62,130.32C846.4,646,797.84,681.81,865.21,642.42Z" style="fill:url(#linear-gradient-5)"/><path d="M509.47,950.06C665.7,999.91,800,876.84,717.21,835.74,642,798.68,435.32,926.49,509.47,950.06Z" style="fill:url(#linear-gradient-6)"/><path d="M638.58,21.42l.53-.57A1.7,1.7,0,0,0,638.58,21.42ZM876.85,702.23c3.8-5.36,8.94-22.53,13.48-30.21,27.58-44.52,27.78-80,27.78-80.84,16.66-83.22,15.15-117.2,4.9-180-8.25-50.6-44.32-123.09-75.57-158-32.2-36-9.51-24.25-40.69-50.52-27.33-30.29-53.82-60.29-68.25-72.36C634.22,43.09,636.57,24.58,638.58,21.42c-.34.37-.84.92-1.47,1.64C635.87,18.14,635,14,635,14s-57,57-69,152c-7.83,62,15.38,126.68,49,168a381.62,381.62,0,0,0,59,58h0c25.4,36.48,39.38,81.49,39.38,129.91,0,121.24-98.34,219.53-219.65,219.53a220.14,220.14,0,0,1-49.13-5.52c-57.24-10.92-90.3-39.8-106.78-59.41-9.45-11.23-13.46-19.42-13.46-19.42,51.28,18.37,108,14.53,142.47-4.52,34.75-19.26,55.77-33.55,72.84-27.92,16.82,5.61,30.21-10.67,18.2-27.54-11.77-16.85-42.4-41-87.88-34.29-34.79,5.07-66.66,29.76-112.24,5.84a97.34,97.34,0,0,1-8.55-5c-3-1.77,9.77,2.69,6.79.68-8.87-4.32-24.57-13.73-28.64-17.07-.68-.56,6.88,2.16,6.2,1.6-42.62-31.45-37.3-52.69-36-66,1.07-10.66,8.81-24.32,21.86-29.86,6.3,3.08,10.23,5.43,10.23,5.43s-2.69-4.92-4.14-7.51c.51-.19,1-.15,1.5-.34,5.16,2.23,16.58,8,22.59,11.57,7.83,4.95,10.32,9.36,10.32,9.36s2.06-1,.54-5.33c-.56-1.77-2.93-7.39-10.68-13.07h.48a91.65,91.65,0,0,1,13.13,8.17c2.19-7.12,6.12-14.56,5.25-27.86-.53-9.35-.28-11.78-2.12-15.39-1.65-3.1.92-4.31,3.78-1.09a29.73,29.73,0,0,0-2.44-7.34v-.24c3.57-11.14,75.53-40.12,80.77-43.51a70.24,70.24,0,0,0,21.17-20.63c4-5.72,7-13.73,7.75-25.89.25-5.48-1.44-9.82-20.5-14-11.44-2.49-29.14-4.91-56.43-7.47-19.9-1.76-31.58-14.68-38.21-26.6-1.21-2.57-2.45-4.9-3.68-7.22a53.41,53.41,0,0,1-2.83-8.36,158.47,158.47,0,0,1,61.28-76.06c1.6-1.31-6.4.33-4.8-1,1.87-1.52,14.06-5.93,16.37-6.92,2.81-1.19-12-6.84-25.16-5.47-13.36,1.35-16.19,2.78-23.32,5.49,3-2.64,12.37-6.1,10.16-6.08-14.4,2-32.3,9.48-47.6,18a9.72,9.72,0,0,1,.92-4.31c-7.13,2.71-24.64,13.67-29.73,23a39.79,39.79,0,0,0,.29-5.35,88.55,88.55,0,0,0-14.6,13.7l-.27.22C258.14,196,221.75,195,191,201.72c-6.74-6.06-17.57-15.23-32.89-45.4-1-1.82-1.6,3.75-2.4,2-6-13.81-9.55-36.44-9-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.87-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.37,12.62-1.38,4-3.32,6.27-4.56,11.29l-.29.46c-.1-1.48.37-6.08,0-5.14A235.4,235.4,0,0,0,95.34,186c-5.49,18-11.88,42.61-12.89,74.57-.24,2.42,0,5.14-.25,7.32-13,14.83-21.86,27.39-25.2,33.91-16.81,26-35.33,66.44-53.29,130.46a319.35,319.35,0,0,1,28.54-50C17.32,416.25,2.89,469.62,0,551.8a436.92,436.92,0,0,1,13.87-50.24C11.29,556.36,17.68,624.3,52.32,701c20.57,45,67.92,136.6,183.62,208h0s39.36,29.3,107,51.26c5,1.81,10.06,3.6,15.23,5.33q-2.43-1-4.71-2A484.9,484.9,0,0,0,492.27,984c175.18.15,226.85-70.2,226.85-70.2l-.51.38q3.71-3.49,7.14-7.26c-27.64,26.08-90.75,27.84-114.3,26,40.22-11.81,66.69-21.81,118.17-41.52q9-3.36,18.48-7.64l2-.94c1.25-.58,2.49-1.13,3.75-1.74a349.3,349.3,0,0,0,70.26-44c51.7-41.3,63-81.56,68.83-108.1-.82,2.54-3.37,8.47-5.17,12.32-13.31,28.48-42.84,46-74.91,61a689.05,689.05,0,0,0,42.38-62.44C865.77,729.39,869,713.15,876.85,702.23Z" style="fill:url(#radial-gradient-2)"/><path d="M813.92,801c21.08-23.24,40-49.82,54.35-80,36.9-77.58,94-206.58,49-341.31C881.77,273.22,833,215,771.11,158.12,670.56,65.76,642.48,24.52,642.48,0c0,0-116.09,129.41-65.74,264.38s153.46,130,221.68,270.87c80.27,165.74-64.95,346.61-185,397.24,7.35-1.63,267-60.38,280.61-208.88C893.68,726.34,887.83,767.41,813.92,801Z" style="fill:url(#linear-gradient-7)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="fill:url(#linear-gradient-8)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="opacity:0.5;isolation:isolate;fill:url(#radial-gradient-3)"/><path d="M158.31,156.47c-1-1.82-1.6,3.75-2.4,2-6-13.81-9.58-36.2-8.72-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.86-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.35,12.38-1.65,4.24-3.35,6.52-4.61,11.77-.39,1.43.39-6.32,0-5.38C84.72,201.68,80.19,271,82.69,268,133.17,214.14,191,201.36,191,201.36c-6.15-4.53-19.53-17.63-32.7-44.89Z" style="fill:url(#linear-gradient-9)"/><path d="M349.84,720.1c-69.72-29.77-149-71.75-146-167.14C207.92,427.35,321,452.18,321,452.18c-4.27,1-15.68,9.16-19.72,17.82-4.27,10.83-12.07,35.28,11.55,60.9,37.09,40.19-76.2,95.36,98.66,199.57,4.41,2.4-41-1.43-61.64-10.36Z" style="fill:url(#linear-gradient-10)"/><path d="M325.07,657.5c49.44,17.21,107,14.19,141.52-4.86,23.09-12.85,52.7-33.43,70.92-28.35-15.78-6.24-27.73-9.15-42.1-9.86-2.45,0-5.38,0-8-.32a136,136,0,0,0-15.76.86c-8.9.82-18.77,6.43-27.74,5.53-.48,0,8.7-3.77,8-3.61-4.75,1-9.92,1.21-15.37,1.88-3.47.39-6.45.82-9.89,1-103,8.73-190-55.81-190-55.81-7.41,25,33.17,74.3,88.52,93.57Z" style="opacity:0.5;isolation:isolate;fill:url(#linear-gradient-11)"/><path d="M813.74,801.65c104.16-102.27,156.86-226.58,134.58-366,0,0,8.9,71.5-24.85,144.63,16.21-71.39,18.1-160.11-25-252C841,205.64,746.45,141.11,710.35,114.19,655.66,73.4,633,31.87,632.57,23.3c-16.34,33.48-65.77,148.2-5.31,247,56.64,92.56,145.86,120,208.33,205C950.67,631.67,813.74,801.65,813.74,801.65Z" style="fill:url(#linear-gradient-12)"/><path d="M798.81,535.55C762.41,460.35,717,427.55,674,392c5,7,6.23,9.47,9,14,37.83,40.32,93.61,138.66,53.11,262.11C659.88,900.48,355,791.06,323,760.32,335.93,894.81,561,959.16,707.6,872,791,793,858.47,658.79,798.81,535.55Z" style="fill:url(#linear-gradient-13)"/></g></g></g></g></svg>
\ No newline at end of file
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker-utils.js b/tools/profiler/tests/browser/serviceworkers/serviceworker-utils.js
new file mode 100644
index 0000000000..16a9f0c91f
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker-utils.js
@@ -0,0 +1,39 @@
+// Most of this file has been stolen from dom/serviceworkers/test/utils.js.
+
+function waitForState(worker, state) {
+  return new Promise((resolve, reject) => {
+    function onStateChange() {
+      if (worker.state === state) {
+        worker.removeEventListener("statechange", onStateChange);
+        resolve();
+      }
+      if (worker.state === "redundant") {
+        worker.removeEventListener("statechange", onStateChange);
+        reject(new Error("The service worker failed to install."));
+      }
+    }
+
+    // First add an event listener, so we won't miss any change that happens
+    // before we check the current state.
+    worker.addEventListener("statechange", onStateChange);
+
+    // Now check if the worker is already in the desired state.
+    onStateChange();
+  });
+}
+
+async function registerServiceWorkerAndWait(serviceWorkerFile) {
+  if (!serviceWorkerFile) {
+    throw new Error(
+      "No service worker filename has been specified. Please specify a valid filename."
+    );
+  }
+
+  console.log(`...registering the serviceworker "${serviceWorkerFile}"`);
+  const reg = await navigator.serviceWorker.register(`./${serviceWorkerFile}`, {
+    scope: "./",
+  });
+  console.log("...waiting for activation");
+  await waitForState(reg.installing, "activated");
+  console.log("...activated!");
+}
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_cache_first.js b/tools/profiler/tests/browser/serviceworkers/serviceworker_cache_first.js
new file mode 100644
index 0000000000..baa07fd6d8
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_cache_first.js
@@ -0,0 +1,34 @@
+const files = ["serviceworker_page.html", "firefox-logo-nightly.svg"];
+const cacheName = "v1";
+
+self.addEventListener("install", event => {
+  performance.mark("__serviceworker_event");
+  console.log("[SW]:", "Install event");
+
+  event.waitUntil(cacheAssets());
+});
+
+async function cacheAssets() {
+  const cache = await caches.open(cacheName);
+  await cache.addAll(files);
+}
+
+self.addEventListener("fetch", event => {
+  performance.mark("__serviceworker_event");
+  console.log("Handling fetch event for", event.request.url);
+  event.respondWith(handleFetch(event.request));
+});
+
+async function handleFetch(request) {
+  const cachedResponse = await caches.match(request);
+  if (cachedResponse) {
+    console.log("Found response in cache:", cachedResponse);
+
+    return cachedResponse;
+  }
+  console.log("No response found in cache. About to fetch from network...");
+
+  const networkResponse = await fetch(request);
+  console.log("Response from network is:", networkResponse);
+  return networkResponse;
+}
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_no_fetch_handler.js b/tools/profiler/tests/browser/serviceworkers/serviceworker_no_fetch_handler.js
new file mode 100644
index 0000000000..f656665ca0
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_no_fetch_handler.js
@@ -0,0 +1,4 @@
+self.addEventListener("install", event => {
+  performance.mark("__serviceworker_event");
+  console.log("[SW]:", "Install event");
+});
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_no_respondWith_in_fetch_handler.js b/tools/profiler/tests/browser/serviceworkers/serviceworker_no_respondWith_in_fetch_handler.js
new file mode 100644
index 0000000000..255c8269a1
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_no_respondWith_in_fetch_handler.js
@@ -0,0 +1,9 @@
+self.addEventListener("install", event => {
+  performance.mark("__serviceworker_event");
+  console.log("[SW]:", "Install event");
+});
+
+self.addEventListener("fetch", event => {
+  performance.mark("__serviceworker_event");
+  console.log("Handling fetch event for", event.request.url);
+});
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_page.html b/tools/profiler/tests/browser/serviceworkers/serviceworker_page.html
new file mode 100644
index 0000000000..1c2100a9d6
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_page.html
@@ -0,0 +1,10 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset='utf-8'>
+    <meta name='viewport' content='initial-scale=1'>
+  </head>
+  <body>
+    <img src='firefox-logo-nightly.svg' width="24">
+  </body>
+</html>
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_register.html b/tools/profiler/tests/browser/serviceworkers/serviceworker_register.html
new file mode 100644
index 0000000000..86719787f4
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_register.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset='utf-8'>
+    <script src='serviceworker-utils.js'></script>
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_simple.html b/tools/profiler/tests/browser/serviceworkers/serviceworker_simple.html
new file mode 100644
index 0000000000..f7c32d02c3
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_simple.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+    Testing
+  </body>
+</html>
diff --git a/tools/profiler/tests/browser/serviceworkers/serviceworker_synthetized_response.js b/tools/profiler/tests/browser/serviceworkers/serviceworker_synthetized_response.js
new file mode 100644
index 0000000000..891b679a5f
--- /dev/null
+++ b/tools/profiler/tests/browser/serviceworkers/serviceworker_synthetized_response.js
@@ -0,0 +1,27 @@
+self.addEventListener("install", event => {
+  performance.mark("__serviceworker_event");
+  dump("[SW]:", "Install event\n");
+});
+
+self.addEventListener("fetch", event => {
+  performance.mark("__serviceworker_event");
+  dump(`Handling fetch event for ${event.request.url}\n`);
+  event.respondWith(handleFetch(event.request));
+});
+
+async function handleFetch(request) {
+  if (request.url.endsWith("-generated.svg")) {
+    dump(
+      "An icon file that should be generated was requested, let's answer directly.\n"
+    );
+    return new Response(
+      `<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 953.37 984"><defs><linearGradient id="linear-gradient" x1="-14706.28" y1="9250.14" x2="-14443.04" y2="9250.14" gradientTransform="matrix(0.76, 0.03, 0.05, -1.12, 11485.47, 11148)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.1" stop-color="#0092f8"/><stop offset="0.31" stop-color="#00abeb"/><stop offset="0.52" stop-color="#00bee1"/><stop offset="0.75" stop-color="#00c8dc"/><stop offset="1" stop-color="#00ccda"/></linearGradient><radialGradient id="radial-gradient" cx="-7588.66" cy="8866.53" r="791.23" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0.02" stop-color="#005fe7"/><stop offset="0.18" stop-color="#0042b4"/><stop offset="0.32" stop-color="#002989"/><stop offset="0.4" stop-color="#002079"/><stop offset="0.47" stop-color="#131d78"/><stop offset="0.66" stop-color="#3b1676"/><stop offset="0.75" stop-color="#4a1475"/></radialGradient><linearGradient id="linear-gradient-2" x1="539.64" y1="254.8" x2="348.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 1, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#000f43" stop-opacity="0.4"/><stop offset="0.48" stop-color="#001962" stop-opacity="0.17"/><stop offset="1" stop-color="#002079" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-3" x1="540.64" y1="254.8" x2="349.2" y2="881.03" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" xlink:href="#linear-gradient-2"/><linearGradient id="linear-gradient-4" x1="-8367.12" y1="7348.87" x2="-8482.36" y2="7357.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#812cc9"/><stop offset="1" stop-color="#005fe7"/></linearGradient><linearGradient id="linear-gradient-5" x1="-8449.89" y1="7496.97" x2="-8341.94" y2="7609.09" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.05" stop-color="#005fe7"/><stop offset="0.18" stop-color="#065de6"/><stop offset="0.35" stop-color="#1856e1"/><stop offset="0.56" stop-color="#354adb"/><stop offset="0.78" stop-color="#5d3ad1"/><stop offset="0.95" stop-color="#812cc9"/></linearGradient><linearGradient id="linear-gradient-6" x1="-8653.41" y1="7245.3" x2="-8422.52" y2="7244.76" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#002079"/><stop offset="0.99" stop-color="#a238ff"/></linearGradient><radialGradient id="radial-gradient-2" cx="644.11" cy="599.83" fx="785.0454815336918" fy="470.6889181532662" r="793.95" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0.2" stop-color="#00fdff"/><stop offset="0.26" stop-color="#0af1ff"/><stop offset="0.37" stop-color="#23d2ff"/><stop offset="0.52" stop-color="#4da0ff"/><stop offset="0.69" stop-color="#855bff"/><stop offset="0.77" stop-color="#a238ff"/><stop offset="0.81" stop-color="#a738fd"/><stop offset="0.86" stop-color="#b539f9"/><stop offset="0.9" stop-color="#cd39f1"/><stop offset="0.96" stop-color="#ee3ae6"/><stop offset="0.98" stop-color="#ff3be0"/></radialGradient><linearGradient id="linear-gradient-7" x1="-7458.97" y1="9093.17" x2="-7531.06" y2="8282.84" gradientTransform="matrix(1.23, 0, 0, -1.22, 9958.21, 11048.11)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00"/><stop offset="0.1" stop-color="#00e244"/><stop offset="0.22" stop-color="#00d694"/><stop offset="0.31" stop-color="#00cfc7"/><stop offset="0.35" stop-color="#00ccda"/><stop offset="0.42" stop-color="#0bc2dd" stop-opacity="0.92"/><stop offset="0.57" stop-color="#29a7e4" stop-opacity="0.72"/><stop offset="0.77" stop-color="#597df0" stop-opacity="0.4"/><stop offset="1" stop-color="#9448ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-8" x1="-8926.61" y1="7680.53" x2="-8790.14" y2="7680.53" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#005fe7"/><stop offset="0.46" stop-color="#0071f3" stop-opacity="0.51"/><stop offset="0.83" stop-color="#007efc" stop-opacity="0.14"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><radialGradient id="radial-gradient-3" cx="-8914.62" cy="7721.05" r="165.97" gradientTransform="matrix(1.22, 0.12, 0.12, -1.22, 10241.06, 10765.32)" gradientUnits="userSpaceOnUse"><stop offset="0.63" stop-color="#ffe302" stop-opacity="0"/><stop offset="0.67" stop-color="#ffe302" stop-opacity="0.05"/><stop offset="0.75" stop-color="#ffe302" stop-opacity="0.19"/><stop offset="0.86" stop-color="#ffe302" stop-opacity="0.4"/><stop offset="0.99" stop-color="#ffe302" stop-opacity="0.7"/></radialGradient><linearGradient id="linear-gradient-9" x1="214.02" y1="2032.47" x2="96.19" y2="2284.31" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, -250.1, 2306.29)" gradientUnits="userSpaceOnUse"><stop offset="0.19" stop-color="#4a1475" stop-opacity="0.5"/><stop offset="0.62" stop-color="#2277ac" stop-opacity="0.23"/><stop offset="0.94" stop-color="#00ccda" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-10" x1="-38.44" y1="278.18" x2="55.67" y2="171.29" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0.01" stop-color="#002079" stop-opacity="0.5"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-11" x1="142.45" y1="96.25" x2="142.5" y2="149.68" gradientTransform="matrix(0.99, 0.1, 0.1, -0.99, 229.04, 745.87)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#4a1475" stop-opacity="0.9"/><stop offset="0.18" stop-color="#6720a2" stop-opacity="0.6"/><stop offset="0.38" stop-color="#812acb" stop-opacity="0.34"/><stop offset="0.57" stop-color="#9332e8" stop-opacity="0.15"/><stop offset="0.76" stop-color="#9e36f9" stop-opacity="0.04"/><stop offset="0.93" stop-color="#a238ff" stop-opacity="0"/></linearGradient><linearGradient id="linear-gradient-12" x1="620.52" y1="947.88" x2="926.18" y2="264.39" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#00ec00" stop-opacity="0"/><stop offset="0.28" stop-color="#00dc6d" stop-opacity="0.5"/><stop offset="0.5" stop-color="#00d1bb" stop-opacity="0.86"/><stop offset="0.6" stop-color="#00ccda"/><stop offset="0.68" stop-color="#04c9db"/><stop offset="0.75" stop-color="#0fc1df"/><stop offset="0.83" stop-color="#23b2e6"/><stop offset="0.9" stop-color="#3e9ef0"/><stop offset="0.98" stop-color="#6184fc"/><stop offset="0.99" stop-color="#6680fe"/></linearGradient><linearGradient id="linear-gradient-13" x1="680.88" y1="554.79" x2="536.1" y2="166.04" gradientTransform="matrix(1, 0, 0, -1, 0, 984)" gradientUnits="userSpaceOnUse"><stop offset="0" stop-color="#0083ff"/><stop offset="0.04" stop-color="#0083ff" stop-opacity="0.92"/><stop offset="0.14" stop-color="#0083ff" stop-opacity="0.71"/><stop offset="0.26" stop-color="#0083ff" stop-opacity="0.52"/><stop offset="0.37" stop-color="#0083ff" stop-opacity="0.36"/><stop offset="0.49" stop-color="#0083ff" stop-opacity="0.23"/><stop offset="0.61" stop-color="#0083ff" stop-opacity="0.13"/><stop offset="0.73" stop-color="#0083ff" stop-opacity="0.06"/><stop offset="0.86" stop-color="#0083ff" stop-opacity="0.01"/><stop offset="1" stop-color="#0083ff" stop-opacity="0"/></linearGradient></defs><title>firefox-logo-nightly</title><g id="Layer_2" data-name="Layer 2"><g id="Layer_1-2" data-name="Layer 1"><g id="Layer_2-2" data-name="Layer 2"><g id="Firefox"><path d="M770.28,91.56c-23.95,27.88-35.1,90.64-10.82,154.26s61.5,49.8,84.7,114.67c30.62,85.6,16.37,200.59,16.37,200.59s36.81,106.61,62.47-6.63C979.79,341.74,770.28,143.94,770.28,91.56Z" style="fill:url(#linear-gradient)"/><path id="_Path_" data-name=" Path " d="M476.92,972.83c245.24,0,443.9-199.74,443.9-446s-198.66-446-443.66-446S33.5,280.51,33.5,526.8C33,773.33,231.92,972.83,476.92,972.83Z" style="fill:url(#radial-gradient)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-2)"/><path d="M810.67,803.64a246.8,246.8,0,0,1-30.12,18.18,705.31,705.31,0,0,0,38.3-63c9.46-10.47,18.13-20.65,25.19-31.65,3.44-5.41,7.31-12.08,11.42-19.82,24.92-44.9,52.4-117.56,53.18-192.2v-5.66a257.25,257.25,0,0,0-5.71-55.75c.2,1.43.38,2.86.56,4.29-.22-1.1-.41-2.21-.64-3.31.37,2,.66,4,1,6,5.09,43.22,1.47,85.37-16.68,116.45-.29.45-.58.88-.87,1.32,9.41-47.23,12.56-99.39,2.09-151.6,0,0-4.19-25.38-35.38-102.44-18-44.35-49.83-80.72-78-107.21-24.69-30.55-47.11-51-59.47-64.06C689.72,126,678.9,105.61,674.45,92.31c-3.85-1.93-53.14-49.81-57.05-51.63-21.51,33.35-89.16,137.67-57,235.15,14.58,44.17,51.47,90,90.07,115.74,1.69,1.94,23,25,33.09,77.16,10.45,53.85,5,95.86-16.54,158C641.73,681.24,577,735.12,516.3,740.63c-129.67,11.78-177.15-65.11-177.15-65.11C385.49,694,436.72,690.17,467.87,671c31.4-19.43,50.39-33.83,65.81-28.15C548.86,648.43,561,632,550.1,615a78.5,78.5,0,0,0-79.4-34.57c-31.43,5.11-60.23,30-101.41,5.89a86.29,86.29,0,0,1-7.73-5.06c-2.71-1.79,8.83,2.72,6.13.69-8-4.35-22.2-13.84-25.88-17.22-.61-.56,6.22,2.18,5.61,1.62-38.51-31.71-33.7-53.13-32.49-66.57,1-10.75,8-24.52,19.75-30.11,5.69,3.11,9.24,5.48,9.24,5.48s-2.43-5-3.74-7.58c.46-.2.9-.15,1.36-.34,4.66,2.25,15,8.1,20.41,11.67,7.07,5,9.33,9.44,9.33,9.44s1.86-1,.48-5.37c-.5-1.78-2.65-7.45-9.65-13.17h.44A81.61,81.61,0,0,1,374.42,478c2-7.18,5.53-14.68,4.75-28.09-.48-9.43-.26-11.87-1.92-15.51-1.49-3.13.83-4.35,3.42-1.1a32.5,32.5,0,0,0-2.21-7.4v-.24c3.23-11.24,68.25-40.46,73-43.88A67.2,67.2,0,0,0,470.59,361c3.62-5.76,6.34-13.85,7-26.11.36-8.84-3.76-14.73-69.51-21.62-18-1.77-28.53-14.8-34.53-26.82-1.09-2.59-2.21-4.94-3.33-7.28a57.68,57.68,0,0,1-2.56-8.43c10.75-30.87,28.81-57,55.37-76.7,1.45-1.32-5.78.34-4.34-1,1.69-1.54,12.71-6,14.79-7,2.54-1.2-10.88-6.9-22.73-5.51-12.07,1.36-14.63,2.8-21.07,5.53,2.67-2.66,11.17-6.15,9.18-6.13-13,2-29.18,9.56-43,18.12a10.66,10.66,0,0,1,.83-4.35c-6.44,2.73-22.26,13.79-26.87,23.14a44.29,44.29,0,0,0,.27-5.4,84.17,84.17,0,0,0-13.19,13.82l-.24.22c-37.36-15-70.23-16-98.05-9.28-6.09-6.11-9.06-1.64-22.91-32.07-.94-1.83.72,1.81,0,0-2.28-5.9,1.39,7.87,0,0-23.28,18.37-53.92,39.19-68.63,53.89-.18.59,17.16-4.9,0,0-6,1.72-5.6,5.28-6.51,37.5-.22,2.44,0,5.18-.22,7.38-11.75,15-19.75,27.64-22.78,34.21-15.19,26.18-31.93,67-48.15,131.55A334.82,334.82,0,0,1,75.2,398.36C61.71,432.63,48.67,486.44,46.07,569.3A482.08,482.08,0,0,1,58.6,518.64,473,473,0,0,0,93.33,719.71c9.33,22.82,24.76,57.46,51,95.4C226.9,902,343.31,956,472.21,956,606.79,956,727.64,897.13,810.67,803.64Z" style="fill:url(#linear-gradient-3)"/><path d="M711.1,866.71c162.87-18.86,235-186.7,142.38-190C769.85,674,634,875.61,711.1,866.71Z" style="fill:url(#linear-gradient-4)"/><path d="M865.21,642.42C977.26,577.21,948,436.34,948,436.34s-43.25,50.24-72.62,130.32C846.4,646,797.84,681.81,865.21,642.42Z" style="fill:url(#linear-gradient-5)"/><path d="M509.47,950.06C665.7,999.91,800,876.84,717.21,835.74,642,798.68,435.32,926.49,509.47,950.06Z" style="fill:url(#linear-gradient-6)"/><path d="M638.58,21.42l.53-.57A1.7,1.7,0,0,0,638.58,21.42ZM876.85,702.23c3.8-5.36,8.94-22.53,13.48-30.21,27.58-44.52,27.78-80,27.78-80.84,16.66-83.22,15.15-117.2,4.9-180-8.25-50.6-44.32-123.09-75.57-158-32.2-36-9.51-24.25-40.69-50.52-27.33-30.29-53.82-60.29-68.25-72.36C634.22,43.09,636.57,24.58,638.58,21.42c-.34.37-.84.92-1.47,1.64C635.87,18.14,635,14,635,14s-57,57-69,152c-7.83,62,15.38,126.68,49,168a381.62,381.62,0,0,0,59,58h0c25.4,36.48,39.38,81.49,39.38,129.91,0,121.24-98.34,219.53-219.65,219.53a220.14,220.14,0,0,1-49.13-5.52c-57.24-10.92-90.3-39.8-106.78-59.41-9.45-11.23-13.46-19.42-13.46-19.42,51.28,18.37,108,14.53,142.47-4.52,34.75-19.26,55.77-33.55,72.84-27.92,16.82,5.61,30.21-10.67,18.2-27.54-11.77-16.85-42.4-41-87.88-34.29-34.79,5.07-66.66,29.76-112.24,5.84a97.34,97.34,0,0,1-8.55-5c-3-1.77,9.77,2.69,6.79.68-8.87-4.32-24.57-13.73-28.64-17.07-.68-.56,6.88,2.16,6.2,1.6-42.62-31.45-37.3-52.69-36-66,1.07-10.66,8.81-24.32,21.86-29.86,6.3,3.08,10.23,5.43,10.23,5.43s-2.69-4.92-4.14-7.51c.51-.19,1-.15,1.5-.34,5.16,2.23,16.58,8,22.59,11.57,7.83,4.95,10.32,9.36,10.32,9.36s2.06-1,.54-5.33c-.56-1.77-2.93-7.39-10.68-13.07h.48a91.65,91.65,0,0,1,13.13,8.17c2.19-7.12,6.12-14.56,5.25-27.86-.53-9.35-.28-11.78-2.12-15.39-1.65-3.1.92-4.31,3.78-1.09a29.73,29.73,0,0,0-2.44-7.34v-.24c3.57-11.14,75.53-40.12,80.77-43.51a70.24,70.24,0,0,0,21.17-20.63c4-5.72,7-13.73,7.75-25.89.25-5.48-1.44-9.82-20.5-14-11.44-2.49-29.14-4.91-56.43-7.47-19.9-1.76-31.58-14.68-38.21-26.6-1.21-2.57-2.45-4.9-3.68-7.22a53.41,53.41,0,0,1-2.83-8.36,158.47,158.47,0,0,1,61.28-76.06c1.6-1.31-6.4.33-4.8-1,1.87-1.52,14.06-5.93,16.37-6.92,2.81-1.19-12-6.84-25.16-5.47-13.36,1.35-16.19,2.78-23.32,5.49,3-2.64,12.37-6.1,10.16-6.08-14.4,2-32.3,9.48-47.6,18a9.72,9.72,0,0,1,.92-4.31c-7.13,2.71-24.64,13.67-29.73,23a39.79,39.79,0,0,0,.29-5.35,88.55,88.55,0,0,0-14.6,13.7l-.27.22C258.14,196,221.75,195,191,201.72c-6.74-6.06-17.57-15.23-32.89-45.4-1-1.82-1.6,3.75-2.4,2-6-13.81-9.55-36.44-9-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.87-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.37,12.62-1.38,4-3.32,6.27-4.56,11.29l-.29.46c-.1-1.48.37-6.08,0-5.14A235.4,235.4,0,0,0,95.34,186c-5.49,18-11.88,42.61-12.89,74.57-.24,2.42,0,5.14-.25,7.32-13,14.83-21.86,27.39-25.2,33.91-16.81,26-35.33,66.44-53.29,130.46a319.35,319.35,0,0,1,28.54-50C17.32,416.25,2.89,469.62,0,551.8a436.92,436.92,0,0,1,13.87-50.24C11.29,556.36,17.68,624.3,52.32,701c20.57,45,67.92,136.6,183.62,208h0s39.36,29.3,107,51.26c5,1.81,10.06,3.6,15.23,5.33q-2.43-1-4.71-2A484.9,484.9,0,0,0,492.27,984c175.18.15,226.85-70.2,226.85-70.2l-.51.38q3.71-3.49,7.14-7.26c-27.64,26.08-90.75,27.84-114.3,26,40.22-11.81,66.69-21.81,118.17-41.52q9-3.36,18.48-7.64l2-.94c1.25-.58,2.49-1.13,3.75-1.74a349.3,349.3,0,0,0,70.26-44c51.7-41.3,63-81.56,68.83-108.1-.82,2.54-3.37,8.47-5.17,12.32-13.31,28.48-42.84,46-74.91,61a689.05,689.05,0,0,0,42.38-62.44C865.77,729.39,869,713.15,876.85,702.23Z" style="fill:url(#radial-gradient-2)"/><path d="M813.92,801c21.08-23.24,40-49.82,54.35-80,36.9-77.58,94-206.58,49-341.31C881.77,273.22,833,215,771.11,158.12,670.56,65.76,642.48,24.52,642.48,0c0,0-116.09,129.41-65.74,264.38s153.46,130,221.68,270.87c80.27,165.74-64.95,346.61-185,397.24,7.35-1.63,267-60.38,280.61-208.88C893.68,726.34,887.83,767.41,813.92,801Z" style="fill:url(#linear-gradient-7)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="fill:url(#linear-gradient-8)"/><path d="M477.59,319.37c.39-8.77-4.16-14.66-76.68-21.46-29.84-2.76-41.26-30.33-44.75-41.94-10.61,27.56-15,56.49-12.64,91.48,1.61,22.92,17,47.52,24.37,62,0,0,1.64-2.13,2.39-2.91,13.86-14.43,71.94-36.42,77.39-39.54C453.69,363.16,476.58,346.44,477.59,319.37Z" style="opacity:0.5;isolation:isolate;fill:url(#radial-gradient-3)"/><path d="M158.31,156.47c-1-1.82-1.6,3.75-2.4,2-6-13.81-9.58-36.2-8.72-52,0,0-12.32,5.61-22.51,29.06-1.89,4.21-3.11,6.54-4.32,8.86-.56.68,1.27-7.7,1-7.24-1.77,3-6.36,7.19-8.35,12.38-1.65,4.24-3.35,6.52-4.61,11.77-.39,1.43.39-6.32,0-5.38C84.72,201.68,80.19,271,82.69,268,133.17,214.14,191,201.36,191,201.36c-6.15-4.53-19.53-17.63-32.7-44.89Z" style="fill:url(#linear-gradient-9)"/><path d="M349.84,720.1c-69.72-29.77-149-71.75-146-167.14C207.92,427.35,321,452.18,321,452.18c-4.27,1-15.68,9.16-19.72,17.82-4.27,10.83-12.07,35.28,11.55,60.9,37.09,40.19-76.2,95.36,98.66,199.57,4.41,2.4-41-1.43-61.64-10.36Z" style="fill:url(#linear-gradient-10)"/><path d="M325.07,657.5c49.44,17.21,107,14.19,141.52-4.86,23.09-12.85,52.7-33.43,70.92-28.35-15.78-6.24-27.73-9.15-42.1-9.86-2.45,0-5.38,0-8-.32a136,136,0,0,0-15.76.86c-8.9.82-18.77,6.43-27.74,5.53-.48,0,8.7-3.77,8-3.61-4.75,1-9.92,1.21-15.37,1.88-3.47.39-6.45.82-9.89,1-103,8.73-190-55.81-190-55.81-7.41,25,33.17,74.3,88.52,93.57Z" style="opacity:0.5;isolation:isolate;fill:url(#linear-gradient-11)"/><path d="M813.74,801.65c104.16-102.27,156.86-226.58,134.58-366,0,0,8.9,71.5-24.85,144.63,16.21-71.39,18.1-160.11-25-252C841,205.64,746.45,141.11,710.35,114.19,655.66,73.4,633,31.87,632.57,23.3c-16.34,33.48-65.77,148.2-5.31,247,56.64,92.56,145.86,120,208.33,205C950.67,631.67,813.74,801.65,813.74,801.65Z" style="fill:url(#linear-gradient-12)"/><path d="M798.81,535.55C762.41,460.35,717,427.55,674,392c5,7,6.23,9.47,9,14,37.83,40.32,93.61,138.66,53.11,262.11C659.88,900.48,355,791.06,323,760.32,335.93,894.81,561,959.16,707.6,872,791,793,858.47,658.79,798.81,535.55Z" style="fill:url(#linear-gradient-13)"/></g></g></g></g></svg>`,
+      { headers: { "content-type": "image/svg+xml" } }
+    );
+  }
+
+  dump(
+    `A normal URL ${request.url} has been requested, let's fetch it from the network.\n`
+  );
+  return fetch(request);
+}
diff --git a/tools/profiler/tests/browser/simple.html b/tools/profiler/tests/browser/simple.html
new file mode 100644
index 0000000000..f7c32d02c3
--- /dev/null
+++ b/tools/profiler/tests/browser/simple.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+  </head>
+  <body>
+    Testing
+  </body>
+</html>
diff --git a/tools/profiler/tests/browser/single_frame.html b/tools/profiler/tests/browser/single_frame.html
new file mode 100644
index 0000000000..ebdfc41da2
--- /dev/null
+++ b/tools/profiler/tests/browser/single_frame.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <title>Single Frame</title>
+</head>
+<body>
+  Single Frame
+</body>
+</html>
diff --git a/tools/profiler/tests/chrome/chrome.ini b/tools/profiler/tests/chrome/chrome.ini
new file mode 100644
index 0000000000..7089b8fb8e
--- /dev/null
+++ b/tools/profiler/tests/chrome/chrome.ini
@@ -0,0 +1,8 @@
+[DEFAULT]
+skip-if = tsan # Bug 1804081
+support-files=profiler_test_utils.js
+
+[test_profile_worker_bug_1428076.html]
+skip-if = os == 'android' && processor == 'arm' # Bug 1541291
+[test_profile_worker.html]
+skip-if = os == 'android' && processor == 'arm' # Bug 1541291
diff --git a/tools/profiler/tests/chrome/profiler_test_utils.js b/tools/profiler/tests/chrome/profiler_test_utils.js
new file mode 100644
index 0000000000..ae9970cbca
--- /dev/null
+++ b/tools/profiler/tests/chrome/profiler_test_utils.js
@@ -0,0 +1,66 @@
+"use strict";
+
+(function() {
+  async function startProfiler(settings) {
+    let startPromise = Services.profiler.StartProfiler(
+      settings.entries,
+      settings.interval,
+      settings.features,
+      settings.threads,
+      0,
+      settings.duration
+    );
+
+    info("Parent Profiler has started");
+
+    await startPromise;
+
+    info("Child profilers have started");
+  }
+
+  function getProfile() {
+    const profile = Services.profiler.getProfileData();
+    info(
+      "We got a profile, run the mochitest with `--keep-open true` to see the logged profile in the Web Console."
+    );
+
+    // Run the mochitest with `--keep-open true` to see the logged profile in the
+    // Web console.
+    console.log(profile);
+
+    return profile;
+  }
+
+  async function stopProfiler() {
+    let stopPromise = Services.profiler.StopProfiler();
+    info("Parent profiler has stopped");
+    await stopPromise;
+    info("Child profilers have stopped");
+  }
+
+  function end(error) {
+    if (error) {
+      ok(false, `We got an error: ${error}`);
+    } else {
+      ok(true, "We ran the whole process");
+    }
+    SimpleTest.finish();
+  }
+
+  async function runTest(settings, workload) {
+    SimpleTest.waitForExplicitFinish();
+    try {
+      await startProfiler(settings);
+      await workload();
+      await getProfile();
+      await stopProfiler();
+      await end();
+    } catch (e) {
+      // By catching and handling the error, we're being nice to mochitest
+      // runners: instead of waiting for the timeout, we fail right away.
+      await end(e);
+    }
+  }
+
+  window.runTest = runTest;
+})();
diff --git a/tools/profiler/tests/chrome/test_profile_worker.html b/tools/profiler/tests/chrome/test_profile_worker.html
new file mode 100644
index 0000000000..8e2bae7fbd
--- /dev/null
+++ b/tools/profiler/tests/chrome/test_profile_worker.html
@@ -0,0 +1,66 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1428076
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1428076</title>
+  <link rel="stylesheet" type="text/css" href="chrome://global/skin"/>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1428076">Mozilla Bug 1428076</a>
+
+<script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+<script type="application/javascript" src="profiler_test_utils.js"></script>
+<script type="application/javascript">
+/* globals runTest */
+
+"use strict";
+
+const settings = {
+  entries: 1000000, // 9MB
+  interval: 1, // ms
+  features: ["js", "stackwalk", "cpu"],
+  threads: ["GeckoMain", "Compositor", "Worker"], // most common combination
+};
+
+const workerCode = `
+  console.log('hello world');
+  setTimeout(() => postMessage('message from worker'), 50);
+`;
+
+function startWorker() {
+  // We use a Blob for the worker content to avoid an external JS file, and data
+  // URLs seem to be blocked in a chrome environment.
+  const workerContent = new Blob(
+    [ workerCode ],
+    { type: "application/javascript" }
+  );
+  const blobURL = URL.createObjectURL(workerContent);
+
+  // We start a worker and then terminate it right away to trigger our bug.
+  info("Starting the worker...");
+  const myWorker = new Worker(blobURL);
+  return { worker: myWorker, url: blobURL };
+}
+
+function workload() {
+  const { worker, url } = startWorker();
+
+  return new Promise(resolve => {
+    worker.onmessage = () => {
+      info("Got a message, terminating the worker.");
+      worker.terminate();
+      URL.revokeObjectURL(url);
+      resolve();
+    };
+  });
+}
+
+runTest(settings, workload);
+
+</script>
+</body>
+</html>
diff --git a/tools/profiler/tests/chrome/test_profile_worker_bug_1428076.html b/tools/profiler/tests/chrome/test_profile_worker_bug_1428076.html
new file mode 100644
index 0000000000..abe0e5748a
--- /dev/null
+++ b/tools/profiler/tests/chrome/test_profile_worker_bug_1428076.html
@@ -0,0 +1,58 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1428076
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1428076</title>
+  <link rel="stylesheet" type="text/css" href="chrome://global/skin"/>
+  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1428076">Mozilla Bug 1428076</a>
+
+<script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+<script type="application/javascript" src="profiler_test_utils.js"></script>
+<script type="application/javascript">
+/** Test for Bug 1428076 **/
+
+/* globals runTest */
+
+"use strict";
+
+const settings = {
+  entries: 1000000, // 9MB
+  interval: 1, // ms
+  features: ["js", "stackwalk"],
+  threads: ["GeckoMain", "Compositor", "Worker"], // most common combination
+};
+
+function workload() {
+  // We use a Blob for the worker content to avoid an external JS file, and data
+  // URLs seem to be blocked in a chrome environment.
+  const workerContent = new Blob(
+    [ "console.log('hello world!')" ],
+    { type: "application/javascript" }
+  );
+  const blobURL = URL.createObjectURL(workerContent);
+
+  // We start a worker and then terminate it right away to trigger our bug.
+  info("Starting the worker, and terminate it right away.");
+  const myWorker = new Worker(blobURL);
+  myWorker.terminate();
+
+  URL.revokeObjectURL(blobURL);
+
+  // We're deferring some little time so that the worker has the time to be
+  // properly cleaned up and the profiler actually saves the worker data.
+  return new Promise(resolve => {
+    setTimeout(resolve, 50);
+  });
+}
+
+runTest(settings, workload);
+
+</script>
+</body>
+</html>
diff --git a/tools/profiler/tests/gtest/GeckoProfiler.cpp b/tools/profiler/tests/gtest/GeckoProfiler.cpp
new file mode 100644
index 0000000000..1bf70bce09
--- /dev/null
+++ b/tools/profiler/tests/gtest/GeckoProfiler.cpp
@@ -0,0 +1,4974 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This file tests a lot of the profiler_*() functions in GeckoProfiler.h.
+// Most of the tests just check that nothing untoward (e.g. crashes, deadlocks)
+// happens when calling these functions. They don't do much inspection of
+// profiler internals.
+
+#include "mozilla/ProfilerThreadPlatformData.h"
+#include "mozilla/ProfilerThreadRegistration.h"
+#include "mozilla/ProfilerThreadRegistrationInfo.h"
+#include "mozilla/ProfilerThreadRegistry.h"
+#include "mozilla/ProfilerUtils.h"
+#include "mozilla/ProgressLogger.h"
+#include "mozilla/UniquePtrExtensions.h"
+
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+#include "prthread.h"
+
+#include "gtest/gtest.h"
+#include "mozilla/gtest/MozAssertions.h"
+
+#include <thread>
+
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#  include <processthreadsapi.h>
+#  include <realtimeapiset.h>
+#elif defined(__APPLE__)
+#  include <mach/thread_act.h>
+#endif
+
+#ifdef MOZ_GECKO_PROFILER
+
+#  include "GeckoProfiler.h"
+#  include "mozilla/ProfilerMarkerTypes.h"
+#  include "mozilla/ProfilerMarkers.h"
+#  include "NetworkMarker.h"
+#  include "platform.h"
+#  include "ProfileBuffer.h"
+#  include "ProfilerControl.h"
+
+#  include "js/Initialization.h"
+#  include "js/Printf.h"
+#  include "jsapi.h"
+#  include "json/json.h"
+#  include "mozilla/Atomics.h"
+#  include "mozilla/BlocksRingBuffer.h"
+#  include "mozilla/DataMutex.h"
+#  include "mozilla/ProfileBufferEntrySerializationGeckoExtensions.h"
+#  include "mozilla/ProfileJSONWriter.h"
+#  include "mozilla/ScopeExit.h"
+#  include "mozilla/net/HttpBaseChannel.h"
+#  include "nsIChannelEventSink.h"
+#  include "nsIThread.h"
+#  include "nsThreadUtils.h"
+
+#  include <cstring>
+#  include <set>
+
+#endif  // MOZ_GECKO_PROFILER
+
+// Note: profiler_init() has already been called in XRE_main(), so we can't
+// test it here. Likewise for profiler_shutdown(), and AutoProfilerInit
+// (which is just an RAII wrapper for profiler_init() and profiler_shutdown()).
+
+using namespace mozilla;
+
+TEST(GeckoProfiler, ProfilerUtils)
+{
+  profiler_init_main_thread_id();
+
+  static_assert(std::is_same_v<decltype(profiler_current_process_id()),
+                               ProfilerProcessId>);
+  static_assert(
+      std::is_same_v<decltype(profiler_current_process_id()),
+                     decltype(baseprofiler::profiler_current_process_id())>);
+  ProfilerProcessId processId = profiler_current_process_id();
+  EXPECT_TRUE(processId.IsSpecified());
+  EXPECT_EQ(processId, baseprofiler::profiler_current_process_id());
+
+  static_assert(
+      std::is_same_v<decltype(profiler_current_thread_id()), ProfilerThreadId>);
+  static_assert(
+      std::is_same_v<decltype(profiler_current_thread_id()),
+                     decltype(baseprofiler::profiler_current_thread_id())>);
+  EXPECT_EQ(profiler_current_thread_id(),
+            baseprofiler::profiler_current_thread_id());
+
+  ProfilerThreadId mainTestThreadId = profiler_current_thread_id();
+  EXPECT_TRUE(mainTestThreadId.IsSpecified());
+
+  ProfilerThreadId mainThreadId = profiler_main_thread_id();
+  EXPECT_TRUE(mainThreadId.IsSpecified());
+
+  EXPECT_EQ(mainThreadId, mainTestThreadId)
+      << "Test should run on the main thread";
+  EXPECT_TRUE(profiler_is_main_thread());
+
+  std::thread testThread([&]() {
+    EXPECT_EQ(profiler_current_process_id(), processId);
+
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+    EXPECT_TRUE(testThreadId.IsSpecified());
+    EXPECT_NE(testThreadId, mainThreadId);
+    EXPECT_FALSE(profiler_is_main_thread());
+
+    EXPECT_EQ(baseprofiler::profiler_current_process_id(), processId);
+    EXPECT_EQ(baseprofiler::profiler_current_thread_id(), testThreadId);
+    EXPECT_EQ(baseprofiler::profiler_main_thread_id(), mainThreadId);
+    EXPECT_FALSE(baseprofiler::profiler_is_main_thread());
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistrationInfo)
+{
+  profiler_init_main_thread_id();
+
+  TimeStamp ts = TimeStamp::Now();
+  {
+    profiler::ThreadRegistrationInfo trInfo{
+        "name", ProfilerThreadId::FromNumber(123), false, ts};
+    EXPECT_STREQ(trInfo.Name(), "name");
+    EXPECT_NE(trInfo.Name(), "name")
+        << "ThreadRegistrationInfo should keep its own copy of the name";
+    EXPECT_EQ(trInfo.RegisterTime(), ts);
+    EXPECT_EQ(trInfo.ThreadId(), ProfilerThreadId::FromNumber(123));
+    EXPECT_EQ(trInfo.IsMainThread(), false);
+  }
+
+  // Make sure the next timestamp will be different from `ts`.
+  while (TimeStamp::Now() == ts) {
+  }
+
+  {
+    profiler::ThreadRegistrationInfo trInfoHere{"Here"};
+    EXPECT_STREQ(trInfoHere.Name(), "Here");
+    EXPECT_NE(trInfoHere.Name(), "Here")
+        << "ThreadRegistrationInfo should keep its own copy of the name";
+    TimeStamp baseRegistrationTime =
+        baseprofiler::detail::GetThreadRegistrationTime();
+    if (baseRegistrationTime) {
+      EXPECT_EQ(trInfoHere.RegisterTime(), baseRegistrationTime);
+    } else {
+      EXPECT_GT(trInfoHere.RegisterTime(), ts);
+    }
+    EXPECT_EQ(trInfoHere.ThreadId(), profiler_current_thread_id());
+    EXPECT_EQ(trInfoHere.ThreadId(), profiler_main_thread_id())
+        << "Gtests are assumed to run on the main thread";
+    EXPECT_EQ(trInfoHere.IsMainThread(), true)
+        << "Gtests are assumed to run on the main thread";
+  }
+
+  {
+    // Sub-thread test.
+    // These will receive sub-thread data (to test move at thread end).
+    TimeStamp tsThread;
+    ProfilerThreadId threadThreadId;
+    UniquePtr<profiler::ThreadRegistrationInfo> trInfoThreadPtr;
+
+    std::thread testThread([&]() {
+      profiler::ThreadRegistrationInfo trInfoThread{"Thread"};
+      EXPECT_STREQ(trInfoThread.Name(), "Thread");
+      EXPECT_NE(trInfoThread.Name(), "Thread")
+          << "ThreadRegistrationInfo should keep its own copy of the name";
+      EXPECT_GT(trInfoThread.RegisterTime(), ts);
+      EXPECT_EQ(trInfoThread.ThreadId(), profiler_current_thread_id());
+      EXPECT_NE(trInfoThread.ThreadId(), profiler_main_thread_id());
+      EXPECT_EQ(trInfoThread.IsMainThread(), false);
+
+      tsThread = trInfoThread.RegisterTime();
+      threadThreadId = trInfoThread.ThreadId();
+      trInfoThreadPtr =
+          MakeUnique<profiler::ThreadRegistrationInfo>(std::move(trInfoThread));
+    });
+    testThread.join();
+
+    ASSERT_NE(trInfoThreadPtr, nullptr);
+    EXPECT_STREQ(trInfoThreadPtr->Name(), "Thread");
+    EXPECT_EQ(trInfoThreadPtr->RegisterTime(), tsThread);
+    EXPECT_EQ(trInfoThreadPtr->ThreadId(), threadThreadId);
+    EXPECT_EQ(trInfoThreadPtr->IsMainThread(), false)
+        << "Gtests are assumed to run on the main thread";
+  }
+}
+
+static constexpr ThreadProfilingFeatures scEachAndAnyThreadProfilingFeatures[] =
+    {ThreadProfilingFeatures::CPUUtilization, ThreadProfilingFeatures::Sampling,
+     ThreadProfilingFeatures::Markers, ThreadProfilingFeatures::Any};
+
+TEST(GeckoProfiler, ThreadProfilingFeaturesType)
+{
+  ASSERT_EQ(static_cast<uint32_t>(ThreadProfilingFeatures::Any), 1u + 2u + 4u)
+      << "This test assumes that there are 3 binary choices 1+2+4; "
+         "Is this test up to date?";
+
+  EXPECT_EQ(Combine(ThreadProfilingFeatures::CPUUtilization,
+                    ThreadProfilingFeatures::Sampling,
+                    ThreadProfilingFeatures::Markers),
+            ThreadProfilingFeatures::Any);
+
+  constexpr ThreadProfilingFeatures allThreadProfilingFeatures[] = {
+      ThreadProfilingFeatures::NotProfiled,
+      ThreadProfilingFeatures::CPUUtilization,
+      ThreadProfilingFeatures::Sampling, ThreadProfilingFeatures::Markers,
+      ThreadProfilingFeatures::Any};
+
+  for (ThreadProfilingFeatures f1 : allThreadProfilingFeatures) {
+    // Combine and Intersect are commutative.
+    for (ThreadProfilingFeatures f2 : allThreadProfilingFeatures) {
+      EXPECT_EQ(Combine(f1, f2), Combine(f2, f1));
+      EXPECT_EQ(Intersect(f1, f2), Intersect(f2, f1));
+    }
+
+    // Combine works like OR.
+    EXPECT_EQ(Combine(f1, f1), f1);
+    EXPECT_EQ(Combine(f1, f1, f1), f1);
+
+    // 'OR NotProfiled' doesn't change anything.
+    EXPECT_EQ(Combine(f1, ThreadProfilingFeatures::NotProfiled), f1);
+
+    // 'OR Any' makes Any.
+    EXPECT_EQ(Combine(f1, ThreadProfilingFeatures::Any),
+              ThreadProfilingFeatures::Any);
+
+    // Intersect works like AND.
+    EXPECT_EQ(Intersect(f1, f1), f1);
+    EXPECT_EQ(Intersect(f1, f1, f1), f1);
+
+    // 'AND NotProfiled' erases anything.
+    EXPECT_EQ(Intersect(f1, ThreadProfilingFeatures::NotProfiled),
+              ThreadProfilingFeatures::NotProfiled);
+
+    // 'AND Any' doesn't change anything.
+    EXPECT_EQ(Intersect(f1, ThreadProfilingFeatures::Any), f1);
+  }
+
+  for (ThreadProfilingFeatures f1 : scEachAndAnyThreadProfilingFeatures) {
+    EXPECT_TRUE(DoFeaturesIntersect(f1, f1));
+
+    // NotProfiled doesn't intersect with any feature.
+    EXPECT_FALSE(DoFeaturesIntersect(f1, ThreadProfilingFeatures::NotProfiled));
+
+    // Any intersects with any feature.
+    EXPECT_TRUE(DoFeaturesIntersect(f1, ThreadProfilingFeatures::Any));
+  }
+}
+
+static void TestConstUnlockedConstReader(
+    const profiler::ThreadRegistration::UnlockedConstReader& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  EXPECT_STREQ(aData.Info().Name(), "Test thread");
+  EXPECT_GE(aData.Info().RegisterTime(), aBeforeRegistration);
+  EXPECT_LE(aData.Info().RegisterTime(), aAfterRegistration);
+  EXPECT_EQ(aData.Info().ThreadId(), aThreadId);
+  EXPECT_FALSE(aData.Info().IsMainThread());
+
+#if (defined(_MSC_VER) || defined(__MINGW32__)) && defined(MOZ_GECKO_PROFILER)
+  HANDLE threadHandle = aData.PlatformDataCRef().ProfiledThread();
+  EXPECT_NE(threadHandle, nullptr);
+  EXPECT_EQ(ProfilerThreadId::FromNumber(::GetThreadId(threadHandle)),
+            aThreadId);
+  // Test calling QueryThreadCycleTime, we cannot assume that it will always
+  // work, but at least it shouldn't crash.
+  ULONG64 cycles;
+  (void)QueryThreadCycleTime(threadHandle, &cycles);
+#elif defined(__APPLE__) && defined(MOZ_GECKO_PROFILER)
+  // Test calling thread_info, we cannot assume that it will always work, but at
+  // least it shouldn't crash.
+  thread_basic_info_data_t threadBasicInfo;
+  mach_msg_type_number_t basicCount = THREAD_BASIC_INFO_COUNT;
+  (void)thread_info(
+      aData.PlatformDataCRef().ProfiledThread(), THREAD_BASIC_INFO,
+      reinterpret_cast<thread_info_t>(&threadBasicInfo), &basicCount);
+#elif (defined(__linux__) || defined(__ANDROID__) || defined(__FreeBSD__)) && \
+    defined(MOZ_GECKO_PROFILER)
+  // Test calling GetClockId, we cannot assume that it will always work, but at
+  // least it shouldn't crash.
+  Maybe<clockid_t> maybeClockId = aData.PlatformDataCRef().GetClockId();
+  if (maybeClockId) {
+    // Test calling clock_gettime, we cannot assume that it will always work,
+    // but at least it shouldn't crash.
+    timespec ts;
+    (void)clock_gettime(*maybeClockId, &ts);
+  }
+#else
+  (void)aData.PlatformDataCRef();
+#endif
+
+  EXPECT_GE(aData.StackTop(), aOnStackObject)
+      << "StackTop should be at &onStackChar, or higher on some "
+         "platforms";
+};
+
+static void TestConstUnlockedConstReaderAndAtomicRW(
+    const profiler::ThreadRegistration::UnlockedConstReaderAndAtomicRW& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReader(aData, aBeforeRegistration, aAfterRegistration,
+                               aOnStackObject, aThreadId);
+
+  (void)aData.ProfilingStackCRef();
+
+  EXPECT_EQ(aData.ProfilingFeatures(), ThreadProfilingFeatures::NotProfiled);
+
+  EXPECT_FALSE(aData.IsSleeping());
+};
+
+static void TestUnlockedConstReaderAndAtomicRW(
+    profiler::ThreadRegistration::UnlockedConstReaderAndAtomicRW& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                          aAfterRegistration, aOnStackObject,
+                                          aThreadId);
+
+  (void)aData.ProfilingStackRef();
+
+  EXPECT_FALSE(aData.IsSleeping());
+  aData.SetSleeping();
+  EXPECT_TRUE(aData.IsSleeping());
+  aData.SetAwake();
+  EXPECT_FALSE(aData.IsSleeping());
+
+  aData.ReinitializeOnResume();
+
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.SetSleeping();
+  // After sleeping, the 2nd+ calls can duplicate.
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.ReinitializeOnResume();
+  // After reinit (and sleeping), the 2nd+ calls can duplicate.
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.SetAwake();
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+};
+
+static void TestConstUnlockedRWForLockedProfiler(
+    const profiler::ThreadRegistration::UnlockedRWForLockedProfiler& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                          aAfterRegistration, aOnStackObject,
+                                          aThreadId);
+
+  // We can't create a PSAutoLock here, so just verify that the call would
+  // compile and return the expected type.
+  static_assert(std::is_same_v<decltype(aData.GetProfiledThreadData(
+                                   std::declval<PSAutoLock>())),
+                               const ProfiledThreadData*>);
+};
+
+static void TestConstUnlockedReaderAndAtomicRWOnThread(
+    const profiler::ThreadRegistration::UnlockedReaderAndAtomicRWOnThread&
+        aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                       aAfterRegistration, aOnStackObject,
+                                       aThreadId);
+
+  EXPECT_EQ(aData.GetJSContext(), nullptr);
+};
+
+static void TestUnlockedRWForLockedProfiler(
+    profiler::ThreadRegistration::UnlockedRWForLockedProfiler& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                       aAfterRegistration, aOnStackObject,
+                                       aThreadId);
+  TestUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                     aAfterRegistration, aOnStackObject,
+                                     aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestUnlockedReaderAndAtomicRWOnThread(
+    profiler::ThreadRegistration::UnlockedReaderAndAtomicRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                             aAfterRegistration, aOnStackObject,
+                                             aThreadId);
+  TestUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                  aAfterRegistration, aOnStackObject,
+                                  aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestConstLockedRWFromAnyThread(
+    const profiler::ThreadRegistration::LockedRWFromAnyThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                             aAfterRegistration, aOnStackObject,
+                                             aThreadId);
+
+  EXPECT_EQ(aData.GetJsFrameBuffer(), nullptr);
+  EXPECT_EQ(aData.GetEventTarget(), nullptr);
+};
+
+static void TestLockedRWFromAnyThread(
+    profiler::ThreadRegistration::LockedRWFromAnyThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                                 aOnStackObject, aThreadId);
+  TestUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                        aAfterRegistration, aOnStackObject,
+                                        aThreadId);
+
+  // We can't create a ProfiledThreadData nor PSAutoLock here, so just verify
+  // that the call would compile and return the expected type.
+  static_assert(std::is_same_v<decltype(aData.SetProfilingFeaturesAndData(
+                                   std::declval<ThreadProfilingFeatures>(),
+                                   std::declval<ProfiledThreadData*>(),
+                                   std::declval<PSAutoLock>())),
+                               void>);
+
+  aData.ResetMainThread(nullptr);
+
+  TimeDuration delay = TimeDuration::FromSeconds(1);
+  TimeDuration running = TimeDuration::FromSeconds(1);
+  aData.GetRunningEventDelay(TimeStamp::Now(), delay, running);
+  EXPECT_TRUE(delay.IsZero());
+  EXPECT_TRUE(running.IsZero());
+
+  aData.StartJSSampling(123u);
+  aData.StopJSSampling();
+};
+
+static void TestConstLockedRWOnThread(
+    const profiler::ThreadRegistration::LockedRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                                 aOnStackObject, aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestLockedRWOnThread(
+    profiler::ThreadRegistration::LockedRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWOnThread(aData, aBeforeRegistration, aAfterRegistration,
+                            aOnStackObject, aThreadId);
+  TestLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                            aOnStackObject, aThreadId);
+
+  // We don't want to really call SetJSContext here, so just verify that
+  // the call would compile and return the expected type.
+  static_assert(
+      std::is_same_v<decltype(aData.SetJSContext(std::declval<JSContext*>())),
+                     void>);
+  aData.ClearJSContext();
+  aData.PollJSSampling();
+};
+
+TEST(GeckoProfiler, ThreadRegistration_DataAccess)
+{
+  using TR = profiler::ThreadRegistration;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+    EXPECT_FALSE(TR::GetOnThreadPtr());
+    EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+    char onStackChar;
+
+    TimeStamp beforeRegistration = TimeStamp::Now();
+    TR tr{"Test thread", &onStackChar};
+    TimeStamp afterRegistration = TimeStamp::Now();
+
+    ASSERT_TRUE(TR::IsRegistered());
+
+    // Note: This test will mostly be about checking the correct access to
+    // thread data, depending on how it's obtained. Not all the functionality
+    // related to that data is tested (e.g., because it involves JS or other
+    // external dependencies that would be difficult to control here.)
+
+    auto TestOnThreadRef = [&](TR::OnThreadRef aOnThreadRef) {
+      // To test const-qualified member functions.
+      const TR::OnThreadRef& onThreadCRef = aOnThreadRef;
+
+      // const UnlockedConstReader (always const)
+
+      TestConstUnlockedConstReader(onThreadCRef.UnlockedConstReaderCRef(),
+                                   beforeRegistration, afterRegistration,
+                                   &onStackChar);
+      onThreadCRef.WithUnlockedConstReader(
+          [&](const TR::UnlockedConstReader& aData) {
+            TestConstUnlockedConstReader(aData, beforeRegistration,
+                                         afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedConstReaderAndAtomicRW
+
+      TestConstUnlockedConstReaderAndAtomicRW(
+          onThreadCRef.UnlockedConstReaderAndAtomicRWCRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedConstReaderAndAtomicRW(
+          [&](const TR::UnlockedConstReaderAndAtomicRW& aData) {
+            TestConstUnlockedConstReaderAndAtomicRW(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedConstReaderAndAtomicRW
+
+      TestUnlockedConstReaderAndAtomicRW(
+          aOnThreadRef.UnlockedConstReaderAndAtomicRWRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedConstReaderAndAtomicRW(
+          [&](TR::UnlockedConstReaderAndAtomicRW& aData) {
+            TestUnlockedConstReaderAndAtomicRW(aData, beforeRegistration,
+                                               afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedRWForLockedProfiler
+
+      TestConstUnlockedRWForLockedProfiler(
+          onThreadCRef.UnlockedRWForLockedProfilerCRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedRWForLockedProfiler(
+          [&](const TR::UnlockedRWForLockedProfiler& aData) {
+            TestConstUnlockedRWForLockedProfiler(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedRWForLockedProfiler
+
+      TestUnlockedRWForLockedProfiler(
+          aOnThreadRef.UnlockedRWForLockedProfilerRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedRWForLockedProfiler(
+          [&](TR::UnlockedRWForLockedProfiler& aData) {
+            TestUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                            afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedReaderAndAtomicRWOnThread
+
+      TestConstUnlockedReaderAndAtomicRWOnThread(
+          onThreadCRef.UnlockedReaderAndAtomicRWOnThreadCRef(),
+          beforeRegistration, afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedReaderAndAtomicRWOnThread(
+          [&](const TR::UnlockedReaderAndAtomicRWOnThread& aData) {
+            TestConstUnlockedReaderAndAtomicRWOnThread(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedReaderAndAtomicRWOnThread
+
+      TestUnlockedReaderAndAtomicRWOnThread(
+          aOnThreadRef.UnlockedReaderAndAtomicRWOnThreadRef(),
+          beforeRegistration, afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedReaderAndAtomicRWOnThread(
+          [&](TR::UnlockedReaderAndAtomicRWOnThread& aData) {
+            TestUnlockedReaderAndAtomicRWOnThread(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // LockedRWFromAnyThread
+      // Note: It cannot directly be accessed on the thread, this will be
+      // tested through LockedRWOnThread.
+
+      // const LockedRWOnThread
+
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      {
+        TR::OnThreadRef::ConstRWOnThreadWithLock constRWOnThreadWithLock =
+            onThreadCRef.ConstLockedRWOnThread();
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestConstLockedRWOnThread(constRWOnThreadWithLock.DataCRef(),
+                                  beforeRegistration, afterRegistration,
+                                  &onStackChar);
+      }
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      onThreadCRef.WithConstLockedRWOnThread(
+          [&](const TR::LockedRWOnThread& aData) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+            TestConstLockedRWOnThread(aData, beforeRegistration,
+                                      afterRegistration, &onStackChar);
+          });
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+      // non-const LockedRWOnThread
+
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      {
+        TR::OnThreadRef::RWOnThreadWithLock rwOnThreadWithLock =
+            aOnThreadRef.LockedRWOnThread();
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestConstLockedRWOnThread(rwOnThreadWithLock.DataCRef(),
+                                  beforeRegistration, afterRegistration,
+                                  &onStackChar);
+        TestLockedRWOnThread(rwOnThreadWithLock.DataRef(), beforeRegistration,
+                             afterRegistration, &onStackChar);
+      }
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      aOnThreadRef.WithLockedRWOnThread([&](TR::LockedRWOnThread& aData) {
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestLockedRWOnThread(aData, beforeRegistration, afterRegistration,
+                             &onStackChar);
+      });
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+    };
+
+    TR::OnThreadPtr onThreadPtr = TR::GetOnThreadPtr();
+    ASSERT_TRUE(onThreadPtr);
+    TestOnThreadRef(*onThreadPtr);
+
+    TR::WithOnThreadRef(
+        [&](TR::OnThreadRef aOnThreadRef) { TestOnThreadRef(aOnThreadRef); });
+
+    EXPECT_TRUE(TR::WithOnThreadRefOr(
+        [&](TR::OnThreadRef aOnThreadRef) {
+          TestOnThreadRef(aOnThreadRef);
+          return true;
+        },
+        false));
+  });
+  testThread.join();
+}
+
+// Thread name if registered, nullptr otherwise.
+static const char* GetThreadName() {
+  return profiler::ThreadRegistration::WithOnThreadRefOr(
+      [](profiler::ThreadRegistration::OnThreadRef onThreadRef) {
+        return onThreadRef.WithUnlockedConstReader(
+            [](const profiler::ThreadRegistration::UnlockedConstReader& aData) {
+              return aData.Info().Name();
+            });
+      },
+      nullptr);
+}
+
+// Get the thread name, as registered in the PRThread, nullptr on failure.
+static const char* GetPRThreadName() {
+  nsIThread* nsThread = NS_GetCurrentThread();
+  if (!nsThread) {
+    return nullptr;
+  }
+  PRThread* prThread = nullptr;
+  if (NS_FAILED(nsThread->GetPRThread(&prThread))) {
+    return nullptr;
+  }
+  if (!prThread) {
+    return nullptr;
+  }
+  return PR_GetThreadName(prThread);
+}
+
+TEST(GeckoProfiler, ThreadRegistration_MainThreadName)
+{
+  EXPECT_TRUE(profiler::ThreadRegistration::IsRegistered());
+  EXPECT_STREQ(GetThreadName(), "GeckoMain");
+
+  // Check that the real thread name (outside the profiler) is *not* GeckoMain.
+  EXPECT_STRNE(GetPRThreadName(), "GeckoMain");
+}
+
+TEST(GeckoProfiler, ThreadRegistration_NestedRegistrations)
+{
+  using TR = profiler::ThreadRegistration;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test actual registrations that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+
+    char onStackChar;
+
+    // Blocks {} are mostly for clarity, but some control on-stack registration
+    // lifetimes.
+
+    // On-stack registration.
+    {
+      TR rt{"Test thread #1", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #1");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #1");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Off-stack registration.
+    {
+      TR::RegisterThread("Test thread #2", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #2");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #2");
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Extra un-registration should be ignored.
+    TR::UnregisterThread();
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested on-stack.
+    {
+      TR rt2{"Test thread #3", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #3");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #3");
+
+      {
+        TR rt3{"Test thread #4", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #3")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #3")
+            << "Nested registration shouldn't change the PRThread name";
+      }
+      ASSERT_TRUE(TR::IsRegistered())
+      << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #3")
+          << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #3");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested off-stack.
+    {
+      TR::RegisterThread("Test thread #5", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #5");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #5");
+
+      {
+        TR::RegisterThread("Test thread #6", &onStackChar);
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #5")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #5")
+            << "Nested registration shouldn't change the PRThread name";
+
+        TR::UnregisterThread();
+        ASSERT_TRUE(TR::IsRegistered())
+        << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetThreadName(), "Test thread #5")
+            << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #5");
+      }
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Nested on- and off-stack.
+    {
+      TR rt2{"Test thread #7", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #7");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #7");
+
+      {
+        TR::RegisterThread("Test thread #8", &onStackChar);
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #7")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #7")
+            << "Nested registration shouldn't change the PRThread name";
+
+        TR::UnregisterThread();
+        ASSERT_TRUE(TR::IsRegistered())
+        << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetThreadName(), "Test thread #7")
+            << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #7");
+      }
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested off- and on-stack.
+    {
+      TR::RegisterThread("Test thread #9", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #9");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #9");
+
+      {
+        TR rt3{"Test thread #10", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #9")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #9")
+            << "Nested registration shouldn't change the PRThread name";
+      }
+      ASSERT_TRUE(TR::IsRegistered())
+      << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #9")
+          << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #9");
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Excess UnregisterThread with on-stack TR.
+    {
+      TR rt2{"Test thread #11", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #11");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #11");
+
+      TR::UnregisterThread();
+      ASSERT_TRUE(TR::IsRegistered())
+      << "On-stack thread should still be registered after off-stack "
+         "un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #11")
+          << "On-stack thread should still be registered after off-stack "
+             "un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #11");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Excess on-thread TR destruction with already-unregistered root off-thread
+    // registration.
+    {
+      TR::RegisterThread("Test thread #12", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #12");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #12");
+
+      {
+        TR rt3{"Test thread #13", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #12")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #12")
+            << "Nested registration shouldn't change the PRThread name";
+
+        // Note that we unregister the root registration, while nested `rt3` is
+        // still alive.
+        TR::UnregisterThread();
+        ASSERT_FALSE(TR::IsRegistered())
+        << "UnregisterThread() of the root RegisterThread() should always work";
+
+        // At this end of this block, `rt3` will be destroyed, but nothing
+        // should happen.
+      }
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    ASSERT_FALSE(TR::IsRegistered());
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistry_DataAccess)
+{
+  using TR = profiler::ThreadRegistration;
+  using TRy = profiler::ThreadRegistry;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+    EXPECT_FALSE(TR::GetOnThreadPtr());
+    EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+    char onStackChar;
+
+    TimeStamp beforeRegistration = TimeStamp::Now();
+    TR tr{"Test thread", &onStackChar};
+    TimeStamp afterRegistration = TimeStamp::Now();
+
+    ASSERT_TRUE(TR::IsRegistered());
+
+    // Note: This test will mostly be about checking the correct access to
+    // thread data, depending on how it's obtained. Not all the functionality
+    // related to that data is tested (e.g., because it involves JS or other
+    // external dependencies that would be difficult to control here.)
+
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+
+    auto testThroughRegistry = [&]() {
+      auto TestOffThreadRef = [&](TRy::OffThreadRef aOffThreadRef) {
+        // To test const-qualified member functions.
+        const TRy::OffThreadRef& offThreadCRef = aOffThreadRef;
+
+        // const UnlockedConstReader (always const)
+
+        TestConstUnlockedConstReader(offThreadCRef.UnlockedConstReaderCRef(),
+                                     beforeRegistration, afterRegistration,
+                                     &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedConstReader(
+            [&](const TR::UnlockedConstReader& aData) {
+              TestConstUnlockedConstReader(aData, beforeRegistration,
+                                           afterRegistration, &onStackChar,
+                                           testThreadId);
+            });
+
+        // const UnlockedConstReaderAndAtomicRW
+
+        TestConstUnlockedConstReaderAndAtomicRW(
+            offThreadCRef.UnlockedConstReaderAndAtomicRWCRef(),
+            beforeRegistration, afterRegistration, &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedConstReaderAndAtomicRW(
+            [&](const TR::UnlockedConstReaderAndAtomicRW& aData) {
+              TestConstUnlockedConstReaderAndAtomicRW(
+                  aData, beforeRegistration, afterRegistration, &onStackChar,
+                  testThreadId);
+            });
+
+        // non-const UnlockedConstReaderAndAtomicRW
+
+        TestUnlockedConstReaderAndAtomicRW(
+            aOffThreadRef.UnlockedConstReaderAndAtomicRWRef(),
+            beforeRegistration, afterRegistration, &onStackChar, testThreadId);
+        aOffThreadRef.WithUnlockedConstReaderAndAtomicRW(
+            [&](TR::UnlockedConstReaderAndAtomicRW& aData) {
+              TestUnlockedConstReaderAndAtomicRW(aData, beforeRegistration,
+                                                 afterRegistration,
+                                                 &onStackChar, testThreadId);
+            });
+
+        // const UnlockedRWForLockedProfiler
+
+        TestConstUnlockedRWForLockedProfiler(
+            offThreadCRef.UnlockedRWForLockedProfilerCRef(), beforeRegistration,
+            afterRegistration, &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedRWForLockedProfiler(
+            [&](const TR::UnlockedRWForLockedProfiler& aData) {
+              TestConstUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                                   afterRegistration,
+                                                   &onStackChar, testThreadId);
+            });
+
+        // non-const UnlockedRWForLockedProfiler
+
+        TestUnlockedRWForLockedProfiler(
+            aOffThreadRef.UnlockedRWForLockedProfilerRef(), beforeRegistration,
+            afterRegistration, &onStackChar, testThreadId);
+        aOffThreadRef.WithUnlockedRWForLockedProfiler(
+            [&](TR::UnlockedRWForLockedProfiler& aData) {
+              TestUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                              afterRegistration, &onStackChar,
+                                              testThreadId);
+            });
+
+        // UnlockedReaderAndAtomicRWOnThread
+        // Note: It cannot directly be accessed off the thread, this will be
+        // tested through LockedRWFromAnyThread.
+
+        // const LockedRWFromAnyThread
+
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        {
+          TRy::OffThreadRef::ConstRWFromAnyThreadWithLock
+              constRWFromAnyThreadWithLock =
+                  offThreadCRef.ConstLockedRWFromAnyThread();
+          if (profiler_current_thread_id() == testThreadId) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+          }
+          TestConstLockedRWFromAnyThread(
+              constRWFromAnyThreadWithLock.DataCRef(), beforeRegistration,
+              afterRegistration, &onStackChar, testThreadId);
+        }
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        offThreadCRef.WithConstLockedRWFromAnyThread(
+            [&](const TR::LockedRWFromAnyThread& aData) {
+              if (profiler_current_thread_id() == testThreadId) {
+                EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+              }
+              TestConstLockedRWFromAnyThread(aData, beforeRegistration,
+                                             afterRegistration, &onStackChar,
+                                             testThreadId);
+            });
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+        // non-const LockedRWFromAnyThread
+
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        {
+          TRy::OffThreadRef::RWFromAnyThreadWithLock rwFromAnyThreadWithLock =
+              aOffThreadRef.LockedRWFromAnyThread();
+          if (profiler_current_thread_id() == testThreadId) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+          }
+          TestLockedRWFromAnyThread(rwFromAnyThreadWithLock.DataRef(),
+                                    beforeRegistration, afterRegistration,
+                                    &onStackChar, testThreadId);
+        }
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        aOffThreadRef.WithLockedRWFromAnyThread(
+            [&](TR::LockedRWFromAnyThread& aData) {
+              if (profiler_current_thread_id() == testThreadId) {
+                EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+              }
+              TestLockedRWFromAnyThread(aData, beforeRegistration,
+                                        afterRegistration, &onStackChar,
+                                        testThreadId);
+            });
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+        // LockedRWOnThread
+        // Note: It can never be accessed off the thread.
+      };
+
+      int ranTest = 0;
+      TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef aOffThreadRef) {
+        TestOffThreadRef(aOffThreadRef);
+        ++ranTest;
+      });
+      EXPECT_EQ(ranTest, 1);
+
+      EXPECT_TRUE(TRy::WithOffThreadRefOr(
+          testThreadId,
+          [&](TRy::OffThreadRef aOffThreadRef) {
+            TestOffThreadRef(aOffThreadRef);
+            return true;
+          },
+          false));
+
+      ranTest = 0;
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+      for (TRy::OffThreadRef offThreadRef : TRy::LockedRegistry{}) {
+        EXPECT_TRUE(TRy::IsRegistryMutexLockedOnCurrentThread() ||
+                    !TR::IsRegistered());
+        if (offThreadRef.UnlockedConstReaderCRef().Info().ThreadId() ==
+            testThreadId) {
+          TestOffThreadRef(offThreadRef);
+          ++ranTest;
+        }
+      }
+      EXPECT_EQ(ranTest, 1);
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+
+      {
+        ranTest = 0;
+        EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+        TRy::LockedRegistry lockedRegistry{};
+        EXPECT_TRUE(TRy::IsRegistryMutexLockedOnCurrentThread() ||
+                    !TR::IsRegistered());
+        for (TRy::OffThreadRef offThreadRef : lockedRegistry) {
+          if (offThreadRef.UnlockedConstReaderCRef().Info().ThreadId() ==
+              testThreadId) {
+            TestOffThreadRef(offThreadRef);
+            ++ranTest;
+          }
+        }
+        EXPECT_EQ(ranTest, 1);
+      }
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+    };
+
+    // Test on the current thread.
+    testThroughRegistry();
+
+    // Test from another thread.
+    std::thread otherThread([&]() {
+      ASSERT_NE(profiler_current_thread_id(), testThreadId);
+      testThroughRegistry();
+
+      // Test that this unregistered thread is really not registered.
+      int ranTest = 0;
+      TRy::WithOffThreadRef(
+          profiler_current_thread_id(),
+          [&](TRy::OffThreadRef aOffThreadRef) { ++ranTest; });
+      EXPECT_EQ(ranTest, 0);
+
+      EXPECT_FALSE(TRy::WithOffThreadRefOr(
+          profiler_current_thread_id(),
+          [&](TRy::OffThreadRef aOffThreadRef) {
+            ++ranTest;
+            return true;
+          },
+          false));
+      EXPECT_EQ(ranTest, 0);
+    });
+    otherThread.join();
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistration_RegistrationEdgeCases)
+{
+  using TR = profiler::ThreadRegistration;
+  using TRy = profiler::ThreadRegistry;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  int registrationCount = 0;
+  int otherThreadLoops = 0;
+  int otherThreadReads = 0;
+
+  // This thread will register and unregister in a loop, with some pauses.
+  // Another thread will attempty to access the test thread, and lock its data.
+  // The main goal is to check edges cases around (un)registrations.
+  std::thread testThread([&]() {
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+
+    const TimeStamp endTestAt = TimeStamp::Now() + TimeDuration::FromSeconds(1);
+
+    std::thread otherThread([&]() {
+      // Initial sleep so that testThread can start its loop.
+      PR_Sleep(PR_MillisecondsToInterval(1));
+
+      while (TimeStamp::Now() < endTestAt) {
+        ++otherThreadLoops;
+
+        TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef
+                                                    aOffThreadRef) {
+          if (otherThreadLoops % 1000 == 0) {
+            PR_Sleep(PR_MillisecondsToInterval(1));
+          }
+          TRy::OffThreadRef::RWFromAnyThreadWithLock rwFromAnyThreadWithLock =
+              aOffThreadRef.LockedRWFromAnyThread();
+          ++otherThreadReads;
+          if (otherThreadReads % 1000 == 0) {
+            PR_Sleep(PR_MillisecondsToInterval(1));
+          }
+        });
+      }
+    });
+
+    while (TimeStamp::Now() < endTestAt) {
+      ASSERT_FALSE(TR::IsRegistered())
+      << "A new std::thread should not start registered";
+      EXPECT_FALSE(TR::GetOnThreadPtr());
+      EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+      char onStackChar;
+
+      TR tr{"Test thread", &onStackChar};
+      ++registrationCount;
+
+      ASSERT_TRUE(TR::IsRegistered());
+
+      int ranTest = 0;
+      TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef aOffThreadRef) {
+        if (registrationCount % 2000 == 0) {
+          PR_Sleep(PR_MillisecondsToInterval(1));
+        }
+        ++ranTest;
+      });
+      EXPECT_EQ(ranTest, 1);
+
+      if (registrationCount % 1000 == 0) {
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    }
+
+    otherThread.join();
+  });
+
+  testThread.join();
+
+  // It's difficult to guess what these numbers should be, but they definitely
+  // should be non-zero. The main goal was to test that nothing goes wrong.
+  EXPECT_GT(registrationCount, 0);
+  EXPECT_GT(otherThreadLoops, 0);
+  EXPECT_GT(otherThreadReads, 0);
+}
+
+#ifdef MOZ_GECKO_PROFILER
+
+TEST(BaseProfiler, BlocksRingBuffer)
+{
+  constexpr uint32_t MBSize = 256;
+  uint8_t buffer[MBSize * 3];
+  for (size_t i = 0; i < MBSize * 3; ++i) {
+    buffer[i] = uint8_t('A' + i);
+  }
+  BlocksRingBuffer rb(BlocksRingBuffer::ThreadSafety::WithMutex,
+                      &buffer[MBSize], MakePowerOfTwo32<MBSize>());
+
+  {
+    nsCString cs("nsCString"_ns);
+    nsString s(u"nsString"_ns);
+    nsAutoCString acs("nsAutoCString"_ns);
+    nsAutoString as(u"nsAutoString"_ns);
+    nsAutoCStringN<8> acs8("nsAutoCStringN"_ns);
+    nsAutoStringN<8> as8(u"nsAutoStringN"_ns);
+    JS::UniqueChars jsuc = JS_smprintf("%s", "JS::UniqueChars");
+
+    rb.PutObjects(cs, s, acs, as, acs8, as8, jsuc);
+  }
+
+  rb.ReadEach([](ProfileBufferEntryReader& aER) {
+    ASSERT_EQ(aER.ReadObject<nsCString>(), "nsCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsString>(), u"nsString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCString>(), "nsAutoCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoString>(), u"nsAutoString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCStringN<8>>(), "nsAutoCStringN"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoStringN<8>>(), u"nsAutoStringN"_ns);
+    auto jsuc2 = aER.ReadObject<JS::UniqueChars>();
+    ASSERT_TRUE(!!jsuc2);
+    ASSERT_TRUE(strcmp(jsuc2.get(), "JS::UniqueChars") == 0);
+  });
+
+  // Everything around the sub-buffer should be unchanged.
+  for (size_t i = 0; i < MBSize; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+  for (size_t i = MBSize * 2; i < MBSize * 3; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+}
+
+// Common JSON checks.
+
+// Check that the given JSON string include no JSON whitespace characters
+// (excluding those in property names and strings).
+void JSONWhitespaceCheck(const char* aOutput) {
+  ASSERT_NE(aOutput, nullptr);
+
+  enum class State { Data, String, StringEscaped };
+  State state = State::Data;
+  size_t length = 0;
+  size_t whitespaces = 0;
+  for (const char* p = aOutput; *p != '\0'; ++p) {
+    ++length;
+    const char c = *p;
+
+    switch (state) {
+      case State::Data:
+        if (c == '\n' || c == '\r' || c == ' ' || c == '\t') {
+          ++whitespaces;
+        } else if (c == '"') {
+          state = State::String;
+        }
+        break;
+
+      case State::String:
+        if (c == '"') {
+          state = State::Data;
+        } else if (c == '\\') {
+          state = State::StringEscaped;
+        }
+        break;
+
+      case State::StringEscaped:
+        state = State::String;
+        break;
+    }
+  }
+
+  EXPECT_EQ(whitespaces, 0u);
+  EXPECT_GT(length, 0u);
+}
+
+// Does the GETTER return a non-null TYPE? (Non-critical)
+#  define EXPECT_HAS_JSON(GETTER, TYPE)              \
+    do {                                             \
+      if ((GETTER).isNull()) {                       \
+        EXPECT_FALSE((GETTER).isNull())              \
+            << #GETTER " doesn't exist or is null";  \
+      } else if (!(GETTER).is##TYPE()) {             \
+        EXPECT_TRUE((GETTER).is##TYPE())             \
+            << #GETTER " didn't return type " #TYPE; \
+      }                                              \
+    } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+#  define ASSERT_HAS_JSON(GETTER, TYPE) \
+    do {                                \
+      ASSERT_FALSE((GETTER).isNull());  \
+      ASSERT_TRUE((GETTER).is##TYPE()); \
+    } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+// If yes, store the reference to Json::Value into VARIABLE.
+#  define GET_JSON(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);         \
+    const Json::Value& VARIABLE = (GETTER)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+// If yes, store the value as `const TYPE` into VARIABLE.
+#  define GET_JSON_VALUE(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);               \
+    const auto VARIABLE = (GETTER).as##TYPE()
+
+// Non-const GET_JSON_VALUE.
+#  define GET_JSON_MUTABLE_VALUE(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);                       \
+    auto VARIABLE = (GETTER).as##TYPE()
+
+// Checks that the GETTER's value is present, is of the expected TYPE, and has
+// the expected VALUE. (Non-critical)
+#  define EXPECT_EQ_JSON(GETTER, TYPE, VALUE)        \
+    do {                                             \
+      if ((GETTER).isNull()) {                       \
+        EXPECT_FALSE((GETTER).isNull())              \
+            << #GETTER " doesn't exist or is null";  \
+      } else if (!(GETTER).is##TYPE()) {             \
+        EXPECT_TRUE((GETTER).is##TYPE())             \
+            << #GETTER " didn't return type " #TYPE; \
+      } else {                                       \
+        EXPECT_EQ((GETTER).as##TYPE(), (VALUE));     \
+      }                                              \
+    } while (false)
+
+// Checks that the GETTER's value is present, and is a valid index into the
+// STRINGTABLE array, pointing at the expected STRING.
+#  define EXPECT_EQ_STRINGTABLE(GETTER, STRINGTABLE, STRING)                 \
+    do {                                                                     \
+      if ((GETTER).isNull()) {                                               \
+        EXPECT_FALSE((GETTER).isNull())                                      \
+            << #GETTER " doesn't exist or is null";                          \
+      } else if (!(GETTER).isUInt()) {                                       \
+        EXPECT_TRUE((GETTER).isUInt()) << #GETTER " didn't return an index"; \
+      } else {                                                               \
+        EXPECT_LT((GETTER).asUInt(), (STRINGTABLE).size());                  \
+        EXPECT_EQ_JSON((STRINGTABLE)[(GETTER).asUInt()], String, (STRING));  \
+      }                                                                      \
+    } while (false)
+
+#  define EXPECT_JSON_ARRAY_CONTAINS(GETTER, TYPE, VALUE)                     \
+    do {                                                                      \
+      if ((GETTER).isNull()) {                                                \
+        EXPECT_FALSE((GETTER).isNull())                                       \
+            << #GETTER " doesn't exist or is null";                           \
+      } else if (!(GETTER).isArray()) {                                       \
+        EXPECT_TRUE((GETTER).is##TYPE()) << #GETTER " is not an array";       \
+      } else if (const Json::ArrayIndex size = (GETTER).size(); size == 0u) { \
+        EXPECT_NE(size, 0u) << #GETTER " is an empty array";                  \
+      } else {                                                                \
+        bool found = false;                                                   \
+        for (Json::ArrayIndex i = 0; i < size; ++i) {                         \
+          if (!(GETTER)[i].is##TYPE()) {                                      \
+            EXPECT_TRUE((GETTER)[i].is##TYPE())                               \
+                << #GETTER "[" << i << "] is not " #TYPE;                     \
+            break;                                                            \
+          }                                                                   \
+          if ((GETTER)[i].as##TYPE() == (VALUE)) {                            \
+            found = true;                                                     \
+            break;                                                            \
+          }                                                                   \
+        }                                                                     \
+        EXPECT_TRUE(found) << #GETTER " doesn't contain " #VALUE;             \
+      }                                                                       \
+    } while (false)
+
+#  define EXPECT_JSON_ARRAY_EXCLUDES(GETTER, TYPE, VALUE)               \
+    do {                                                                \
+      if ((GETTER).isNull()) {                                          \
+        EXPECT_FALSE((GETTER).isNull())                                 \
+            << #GETTER " doesn't exist or is null";                     \
+      } else if (!(GETTER).isArray()) {                                 \
+        EXPECT_TRUE((GETTER).is##TYPE()) << #GETTER " is not an array"; \
+      } else {                                                          \
+        const Json::ArrayIndex size = (GETTER).size();                  \
+        for (Json::ArrayIndex i = 0; i < size; ++i) {                   \
+          if (!(GETTER)[i].is##TYPE()) {                                \
+            EXPECT_TRUE((GETTER)[i].is##TYPE())                         \
+                << #GETTER "[" << i << "] is not " #TYPE;               \
+            break;                                                      \
+          }                                                             \
+          if ((GETTER)[i].as##TYPE() == (VALUE)) {                      \
+            EXPECT_TRUE((GETTER)[i].as##TYPE() != (VALUE))              \
+                << #GETTER " contains " #VALUE;                         \
+            break;                                                      \
+          }                                                             \
+        }                                                               \
+      }                                                                 \
+    } while (false)
+
+// Check that the given process root contains all the expected properties.
+static void JSONRootCheck(const Json::Value& aRoot,
+                          bool aWithMainThread = true) {
+  ASSERT_TRUE(aRoot.isObject());
+
+  EXPECT_HAS_JSON(aRoot["libs"], Array);
+
+  GET_JSON(meta, aRoot["meta"], Object);
+  EXPECT_HAS_JSON(meta["version"], UInt);
+  EXPECT_HAS_JSON(meta["startTime"], Double);
+  EXPECT_HAS_JSON(meta["profilingStartTime"], Double);
+  EXPECT_HAS_JSON(meta["contentEarliestTime"], Double);
+  EXPECT_HAS_JSON(meta["profilingEndTime"], Double);
+
+  EXPECT_HAS_JSON(aRoot["pages"], Array);
+
+  EXPECT_HAS_JSON(aRoot["profilerOverhead"], Object);
+
+  // "counters" is only present if there is any data to report.
+  // Test that expect "counters" should test for its presence first.
+  if (aRoot.isMember("counters")) {
+    // We have "counters", test their overall validity.
+    GET_JSON(counters, aRoot["counters"], Array);
+    for (const Json::Value& counter : counters) {
+      ASSERT_TRUE(counter.isObject());
+      EXPECT_HAS_JSON(counter["name"], String);
+      EXPECT_HAS_JSON(counter["category"], String);
+      EXPECT_HAS_JSON(counter["description"], String);
+      GET_JSON(sampleGroups, counter["sample_groups"], Array);
+      for (const Json::Value& sampleGroup : sampleGroups) {
+        ASSERT_TRUE(sampleGroup.isObject());
+        EXPECT_HAS_JSON(sampleGroup["id"], UInt);
+
+        GET_JSON(samples, sampleGroup["samples"], Object);
+        GET_JSON(samplesSchema, samples["schema"], Object);
+        EXPECT_GE(samplesSchema.size(), 3u);
+        GET_JSON_VALUE(samplesTime, samplesSchema["time"], UInt);
+        GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+        GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+        GET_JSON(samplesData, samples["data"], Array);
+        double previousTime = 0.0;
+        for (const Json::Value& sample : samplesData) {
+          ASSERT_TRUE(sample.isArray());
+          GET_JSON_VALUE(time, sample[samplesTime], Double);
+          EXPECT_GE(time, previousTime);
+          previousTime = time;
+          if (sample.isValidIndex(samplesNumber)) {
+            EXPECT_HAS_JSON(sample[samplesNumber], UInt64);
+          }
+          if (sample.isValidIndex(samplesCount)) {
+            EXPECT_HAS_JSON(sample[samplesCount], Int64);
+          }
+        }
+      }
+    }
+  }
+
+  GET_JSON(threads, aRoot["threads"], Array);
+  const Json::ArrayIndex threadCount = threads.size();
+  for (Json::ArrayIndex i = 0; i < threadCount; ++i) {
+    GET_JSON(thread, threads[i], Object);
+    EXPECT_HAS_JSON(thread["processType"], String);
+    EXPECT_HAS_JSON(thread["name"], String);
+    EXPECT_HAS_JSON(thread["registerTime"], Double);
+    GET_JSON(samples, thread["samples"], Object);
+    EXPECT_HAS_JSON(thread["markers"], Object);
+    EXPECT_HAS_JSON(thread["pid"], Int64);
+    EXPECT_HAS_JSON(thread["tid"], Int64);
+    GET_JSON(stackTable, thread["stackTable"], Object);
+    GET_JSON(frameTable, thread["frameTable"], Object);
+    GET_JSON(stringTable, thread["stringTable"], Array);
+
+    GET_JSON(stackTableSchema, stackTable["schema"], Object);
+    EXPECT_GE(stackTableSchema.size(), 2u);
+    GET_JSON_VALUE(stackTablePrefix, stackTableSchema["prefix"], UInt);
+    GET_JSON_VALUE(stackTableFrame, stackTableSchema["frame"], UInt);
+    GET_JSON(stackTableData, stackTable["data"], Array);
+
+    GET_JSON(frameTableSchema, frameTable["schema"], Object);
+    EXPECT_GE(frameTableSchema.size(), 1u);
+    GET_JSON_VALUE(frameTableLocation, frameTableSchema["location"], UInt);
+    GET_JSON(frameTableData, frameTable["data"], Array);
+
+    GET_JSON(samplesSchema, samples["schema"], Object);
+    GET_JSON_VALUE(sampleStackIndex, samplesSchema["stack"], UInt);
+    GET_JSON(samplesData, samples["data"], Array);
+    for (const Json::Value& sample : samplesData) {
+      ASSERT_TRUE(sample.isArray());
+      if (sample.isValidIndex(sampleStackIndex)) {
+        if (!sample[sampleStackIndex].isNull()) {
+          GET_JSON_MUTABLE_VALUE(stack, sample[sampleStackIndex], UInt);
+          EXPECT_TRUE(stackTableData.isValidIndex(stack));
+          for (;;) {
+            // `stack` (from the sample, or from the callee frame's "prefix" in
+            // the previous loop) points into the stackTable.
+            GET_JSON(stackTableEntry, stackTableData[stack], Array);
+            GET_JSON_VALUE(frame, stackTableEntry[stackTableFrame], UInt);
+
+            // The stackTable entry's "frame" points into the frameTable.
+            EXPECT_TRUE(frameTableData.isValidIndex(frame));
+            GET_JSON(frameTableEntry, frameTableData[frame], Array);
+            GET_JSON_VALUE(location, frameTableEntry[frameTableLocation], UInt);
+
+            // The frameTable entry's "location" points at a string.
+            EXPECT_TRUE(stringTable.isValidIndex(location));
+
+            // The stackTable entry's "prefix" is null for the root frame.
+            if (stackTableEntry[stackTablePrefix].isNull()) {
+              break;
+            }
+            // Otherwise it recursively points at the caller in the stackTable.
+            GET_JSON_VALUE(prefix, stackTableEntry[stackTablePrefix], UInt);
+            EXPECT_TRUE(stackTableData.isValidIndex(prefix));
+            stack = prefix;
+          }
+        }
+      }
+    }
+  }
+
+  if (aWithMainThread) {
+    ASSERT_GT(threadCount, 0u);
+    GET_JSON(thread0, threads[0], Object);
+    EXPECT_EQ_JSON(thread0["name"], String, "GeckoMain");
+  }
+
+  EXPECT_HAS_JSON(aRoot["pausedRanges"], Array);
+
+  const Json::Value& processes = aRoot["processes"];
+  if (!processes.isNull()) {
+    ASSERT_TRUE(processes.isArray());
+    const Json::ArrayIndex processCount = processes.size();
+    for (Json::ArrayIndex i = 0; i < processCount; ++i) {
+      GET_JSON(process, processes[i], Object);
+      JSONRootCheck(process, aWithMainThread);
+    }
+  }
+
+  GET_JSON(profilingLog, aRoot["profilingLog"], Object);
+  EXPECT_EQ(profilingLog.size(), 1u);
+  for (auto it = profilingLog.begin(); it != profilingLog.end(); ++it) {
+    // The key should be a pid.
+    const auto key = it.name();
+    for (const auto letter : key) {
+      EXPECT_GE(letter, '0');
+      EXPECT_LE(letter, '9');
+    }
+    // And the value should be an object.
+    GET_JSON(logForPid, profilingLog[key], Object);
+    // Its content is not defined, but we expect at least these:
+    EXPECT_HAS_JSON(logForPid["profilingLogBegin_TSms"], Double);
+    EXPECT_HAS_JSON(logForPid["profilingLogEnd_TSms"], Double);
+  }
+}
+
+// Check that various expected top properties are in the JSON, and then call the
+// provided `aJSONCheckFunction` with the JSON root object.
+template <typename JSONCheckFunction>
+void JSONOutputCheck(const char* aOutput,
+                     JSONCheckFunction&& aJSONCheckFunction) {
+  ASSERT_NE(aOutput, nullptr);
+
+  JSONWhitespaceCheck(aOutput);
+
+  // Extract JSON.
+  Json::Value parsedRoot;
+  Json::CharReaderBuilder builder;
+  const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  ASSERT_TRUE(
+      reader->parse(aOutput, strchr(aOutput, '\0'), &parsedRoot, nullptr));
+
+  JSONRootCheck(parsedRoot);
+
+  std::forward<JSONCheckFunction>(aJSONCheckFunction)(parsedRoot);
+}
+
+// Returns `static_cast<SamplingState>(-1)` if callback could not be installed.
+static SamplingState WaitForSamplingState() {
+  Atomic<int> samplingState{-1};
+
+  if (!profiler_callback_after_sampling([&](SamplingState aSamplingState) {
+        samplingState = static_cast<int>(aSamplingState);
+      })) {
+    return static_cast<SamplingState>(-1);
+  }
+
+  while (samplingState == -1) {
+  }
+
+  return static_cast<SamplingState>(static_cast<int>(samplingState));
+}
+
+typedef Vector<const char*> StrVec;
+
+static void InactiveFeaturesAndParamsCheck() {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeTabID;
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::NativeAllocations));
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeTabID);
+
+  ASSERT_TRUE(entries == 0);
+  ASSERT_TRUE(duration == Nothing());
+  ASSERT_TRUE(interval == 0);
+  ASSERT_TRUE(features == 0);
+  ASSERT_TRUE(filters.empty());
+  ASSERT_TRUE(activeTabID == 0);
+}
+
+static void ActiveParamsCheck(int aEntries, double aInterval,
+                              uint32_t aFeatures, const char** aFilters,
+                              size_t aFiltersLen, uint64_t aActiveTabID,
+                              const Maybe<double>& aDuration = Nothing()) {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeTabID;
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeTabID);
+
+  ASSERT_TRUE(entries == aEntries);
+  ASSERT_TRUE(duration == aDuration);
+  ASSERT_TRUE(interval == aInterval);
+  ASSERT_TRUE(features == aFeatures);
+  ASSERT_TRUE(filters.length() == aFiltersLen);
+  ASSERT_TRUE(activeTabID == aActiveTabID);
+  for (size_t i = 0; i < aFiltersLen; i++) {
+    ASSERT_TRUE(strcmp(filters[i], aFilters[i]) == 0);
+  }
+}
+
+TEST(GeckoProfiler, FeaturesAndParams)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  // Try a couple of features and filters.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+#  define PROFILER_DEFAULT_DURATION 20 /* seconds, for tests only */
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 100,
+                   Some(PROFILER_DEFAULT_DURATION));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 100,
+                      Some(PROFILER_DEFAULT_DURATION));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try some different features and filters.
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    // Testing with some arbitrary buffer size (as could be provided by
+    // external code), which we convert to the appropriate power of 2.
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try with no duration
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try all supported features, and filters that match all threads.
+  {
+    uint32_t availableFeatures = profiler_get_available_features();
+    const char* filters[] = {""};
+
+    profiler_start(PowerOfTwo32(88888), 10, availableFeatures, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PowerOfTwo32(88888).Value(), 10, availableFeatures,
+                      filters, MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    // Don't call profiler_stop() here.
+  }
+
+  // Try no features, and filters that match no threads.
+  {
+    uint32_t features = 0;
+    const char* filters[] = {"NoThreadWillMatchThis"};
+
+    // Second profiler_start() call in a row without an intervening
+    // profiler_stop(); this will do an implicit profiler_stop() and restart.
+    profiler_start(PowerOfTwo32(0), 0, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(0.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    // Entries and intervals go to defaults if 0 is specified.
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+
+    // These calls are no-ops.
+    profiler_stop();
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, EnsureStarted)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  uint32_t features = ProfilerFeature::JS;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+  {
+    // Inactive -> Active
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+  }
+
+  {
+    // Active -> Active with same settings
+
+    Maybe<ProfilerBufferInfo> info0 = profiler_get_buffer_info();
+    ASSERT_TRUE(info0->mRangeEnd > 0);
+
+    // First, write some samples into the buffer.
+    PR_Sleep(PR_MillisecondsToInterval(500));
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+    ASSERT_TRUE(info1->mRangeEnd > info0->mRangeEnd);
+
+    // Call profiler_ensure_started with the same settings as before.
+    // This operation must not clear our buffer!
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+
+    // Check that our position in the buffer stayed the same or advanced, but
+    // not by much, and the range-start after profiler_ensure_started shouldn't
+    // have passed the range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeEnd >= info1->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeEnd - info1->mRangeEnd <
+                info1->mRangeEnd - info0->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeStart < info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Active with *different* settings
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+
+    // Call profiler_ensure_started with a different feature set than the one
+    // it's currently running with. This is supposed to stop and restart the
+    // profiler, thereby discarding the buffer contents.
+    uint32_t differentFeatures = features | ProfilerFeature::CPUUtilization;
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            differentFeatures, filters,
+                            MOZ_ARRAY_LENGTH(filters), 0);
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, differentFeatures, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    // Check the the buffer was cleared, so its range-start should be at/after
+    // its range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeStart >= info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Inactive
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, MultiRegistration)
+{
+  // This whole test only checks that function calls don't crash, they don't
+  // actually verify that threads get profiled or not.
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread, no unreg", &top);
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() { profiler_unregister_thread(); });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread 1st", &top);
+      profiler_unregister_thread();
+      profiler_register_thread("thread 2nd", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread once", &top);
+      profiler_register_thread("thread again", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread to unreg twice", &top);
+      profiler_unregister_thread();
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+}
+
+TEST(GeckoProfiler, DifferentThreads)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  // Control the profiler on a background thread and verify flags on the
+  // main thread.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() {
+                                 profiler_start(PROFILER_DEFAULT_ENTRIES,
+                                                PROFILER_DEFAULT_INTERVAL,
+                                                features, filters,
+                                                MOZ_ARRAY_LENGTH(filters), 0);
+                               }),
+        NS_DISPATCH_SYNC);
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { profiler_stop(); }),
+        NS_DISPATCH_SYNC);
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Control the profiler on the main thread and verify flags on a
+  // background thread.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    thread->Dispatch(
+        NS_NewRunnableFunction(
+            "GeckoProfiler_DifferentThreads_Test::TestBody",
+            [&]() {
+              ASSERT_TRUE(profiler_is_active());
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::MainThreadIO));
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::IPCMessages));
+
+              ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                                PROFILER_DEFAULT_INTERVAL, features, filters,
+                                MOZ_ARRAY_LENGTH(filters), 0);
+            }),
+        NS_DISPATCH_SYNC);
+
+    profiler_stop();
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { InactiveFeaturesAndParamsCheck(); }),
+        NS_DISPATCH_SYNC);
+  }
+
+  thread->Shutdown();
+}
+
+TEST(GeckoProfiler, GetBacktrace)
+{
+  ASSERT_TRUE(!profiler_get_backtrace());
+
+  {
+    uint32_t features = ProfilerFeature::StackWalk;
+    const char* filters[] = {"GeckoMain"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    // These will be destroyed while the profiler is active.
+    static const int N = 100;
+    {
+      UniqueProfilerBacktrace u[N];
+      for (int i = 0; i < N; i++) {
+        u[i] = profiler_get_backtrace();
+        ASSERT_TRUE(u[i]);
+      }
+    }
+
+    // These will be destroyed after the profiler stops.
+    UniqueProfilerBacktrace u[N];
+    for (int i = 0; i < N; i++) {
+      u[i] = profiler_get_backtrace();
+      ASSERT_TRUE(u[i]);
+    }
+
+    profiler_stop();
+  }
+
+  ASSERT_TRUE(!profiler_get_backtrace());
+}
+
+TEST(GeckoProfiler, Pause)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test must run on the main thread";
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain", "Profiled GeckoProfiler.Pause"};
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                   features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - before start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - before start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                  features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+  }}.join();
+
+  // Check that we are writing samples while not paused.
+  Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  // Check that we are writing markers while not paused.
+  ASSERT_TRUE(profiler_thread_is_being_profiled_for_markers());
+  ASSERT_TRUE(
+      profiler_thread_is_being_profiled_for_markers(ProfilerThreadId{}));
+  ASSERT_TRUE(profiler_thread_is_being_profiled_for_markers(
+      profiler_current_thread_id()));
+  ASSERT_TRUE(
+      profiler_thread_is_being_profiled_for_markers(profiler_main_thread_id()));
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Not paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  profiler_pause();
+
+  ASSERT_TRUE(profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+  }
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers());
+  ASSERT_TRUE(
+      !profiler_thread_is_being_profiled_for_markers(ProfilerThreadId{}));
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers(
+      profiler_current_thread_id()));
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers(
+      profiler_main_thread_id()));
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after pause");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after pause");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+
+  // Check that we are not writing samples while paused.
+  info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+
+  // Check that we are now writing markers while paused.
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+  PROFILER_MARKER_UNTYPED("Paused v2", OTHER, {});
+  Maybe<ProfilerBufferInfo> info3 = profiler_get_buffer_info();
+  ASSERT_TRUE(info2->mRangeEnd == info3->mRangeEnd);
+
+  profiler_resume();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                  features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after resume");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after resume");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+  }}.join();
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD("Ignored GeckoProfiler.Pause - after stop");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after stop");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+}
+
+TEST(GeckoProfiler, Markers)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  PROFILER_MARKER("tracing event", OTHER, {}, Tracing, "A");
+  PROFILER_MARKER("tracing start", OTHER, MarkerTiming::IntervalStart(),
+                  Tracing, "A");
+  PROFILER_MARKER("tracing end", OTHER, MarkerTiming::IntervalEnd(), Tracing,
+                  "A");
+
+  auto bt = profiler_capture_backtrace();
+  PROFILER_MARKER("tracing event with stack", OTHER,
+                  MarkerStack::TakeBacktrace(std::move(bt)), Tracing, "B");
+
+  { AUTO_PROFILER_TRACING_MARKER("C", "auto tracing", OTHER); }
+
+  PROFILER_MARKER_UNTYPED("M1", OTHER, {});
+  PROFILER_MARKER_UNTYPED("M3", OTHER, {});
+
+  // Create three strings: two that are the maximum allowed length, and one that
+  // is one char longer.
+  static const size_t kMax = ProfileBuffer::kMaxFrameKeyLength;
+  UniquePtr<char[]> okstr1 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> okstr2 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> longstr = MakeUnique<char[]>(kMax + 1);
+  UniquePtr<char[]> longstrCut = MakeUnique<char[]>(kMax + 1);
+  for (size_t i = 0; i < kMax; i++) {
+    okstr1[i] = 'a';
+    okstr2[i] = 'b';
+    longstr[i] = 'c';
+    longstrCut[i] = 'c';
+  }
+  okstr1[kMax - 1] = '\0';
+  okstr2[kMax - 1] = '\0';
+  longstr[kMax] = '\0';
+  longstrCut[kMax] = '\0';
+  // Should be output as-is.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, "");
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, okstr1.get());
+  // Should be output as label + space + okstr2.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("okstr2", LAYOUT, okstr2.get());
+  // Should be output with kMax length, ending with "...\0".
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, longstr.get());
+  ASSERT_EQ(longstrCut[kMax - 4], 'c');
+  longstrCut[kMax - 4] = '.';
+  ASSERT_EQ(longstrCut[kMax - 3], 'c');
+  longstrCut[kMax - 3] = '.';
+  ASSERT_EQ(longstrCut[kMax - 2], 'c');
+  longstrCut[kMax - 2] = '.';
+  ASSERT_EQ(longstrCut[kMax - 1], 'c');
+  longstrCut[kMax - 1] = '\0';
+
+  // Test basic markers 2.0.
+  EXPECT_TRUE(
+      profiler_add_marker("default-templated markers 2.0 with empty options",
+                          geckoprofiler::category::OTHER, {}));
+
+  PROFILER_MARKER_UNTYPED(
+      "default-templated markers 2.0 with option", OTHER,
+      MarkerStack::TakeBacktrace(profiler_capture_backtrace()));
+
+  PROFILER_MARKER("explicitly-default-templated markers 2.0 with empty options",
+                  OTHER, {}, NoPayload);
+
+  EXPECT_TRUE(profiler_add_marker(
+      "explicitly-default-templated markers 2.0 with option",
+      geckoprofiler::category::OTHER, {},
+      ::geckoprofiler::markers::NoPayload{}));
+
+  // Used in markers below.
+  TimeStamp ts1 = TimeStamp::Now();
+
+  // Sleep briefly to ensure a sample is taken and the pending markers are
+  // processed.
+  PR_Sleep(PR_MillisecondsToInterval(500));
+
+  // Used in markers below.
+  TimeStamp ts2 = TimeStamp::Now();
+  // ts1 and ts2 should be different thanks to the sleep.
+  EXPECT_NE(ts1, ts2);
+
+  // Test most marker payloads.
+
+  // Keep this one first! (It's used to record `ts1` and `ts2`, to compare
+  // to serialized numbers in other markers.)
+  EXPECT_TRUE(profiler_add_marker("FirstMarker", geckoprofiler::category::OTHER,
+                                  MarkerTiming::Interval(ts1, ts2),
+                                  geckoprofiler::markers::TextMarker{},
+                                  "First Marker"));
+
+  // User-defined marker type with different properties, and fake schema.
+  struct GtestMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter, int aInt,
+        double aDouble, const mozilla::ProfilerString8View& aText,
+        const mozilla::ProfilerString8View& aUniqueText,
+        const mozilla::TimeStamp& aTime) {
+      aWriter.NullProperty("null");
+      aWriter.BoolProperty("bool-false", false);
+      aWriter.BoolProperty("bool-true", true);
+      aWriter.IntProperty("int", aInt);
+      aWriter.DoubleProperty("double", aDouble);
+      aWriter.StringProperty("text", aText);
+      aWriter.UniqueStringProperty("unique text", aUniqueText);
+      aWriter.UniqueStringProperty("unique text again", aUniqueText);
+      aWriter.TimeProperty("time", aTime);
+    }
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      // Note: This is an test function that is not intended to actually output
+      // that correctly matches StreamJSONMarkerData data above! Instead we only
+      // test that it outputs the expected JSON at the end.
+      using MS = mozilla::MarkerSchema;
+      MS schema{MS::Location::MarkerChart,      MS::Location::MarkerTable,
+                MS::Location::TimelineOverview, MS::Location::TimelineMemory,
+                MS::Location::TimelineIPC,      MS::Location::TimelineFileIO,
+                MS::Location::StackChart};
+      // All label functions.
+      schema.SetChartLabel("chart label");
+      schema.SetTooltipLabel("tooltip label");
+      schema.SetTableLabel("table label");
+      // All data functions, all formats, all "searchable" values.
+      schema.AddKeyFormat("key with url", MS::Format::Url);
+      schema.AddKeyLabelFormat("key with label filePath", "label filePath",
+                               MS::Format::FilePath);
+      schema.AddKeyFormatSearchable("key with string not-searchable",
+                                    MS::Format::String,
+                                    MS::Searchable::NotSearchable);
+      schema.AddKeyLabelFormatSearchable("key with label duration searchable",
+                                         "label duration", MS::Format::Duration,
+                                         MS::Searchable::Searchable);
+      schema.AddKeyFormat("key with time", MS::Format::Time);
+      schema.AddKeyFormat("key with seconds", MS::Format::Seconds);
+      schema.AddKeyFormat("key with milliseconds", MS::Format::Milliseconds);
+      schema.AddKeyFormat("key with microseconds", MS::Format::Microseconds);
+      schema.AddKeyFormat("key with nanoseconds", MS::Format::Nanoseconds);
+      schema.AddKeyFormat("key with bytes", MS::Format::Bytes);
+      schema.AddKeyFormat("key with percentage", MS::Format::Percentage);
+      schema.AddKeyFormat("key with integer", MS::Format::Integer);
+      schema.AddKeyFormat("key with decimal", MS::Format::Decimal);
+      schema.AddStaticLabelValue("static label", "static value");
+      return schema;
+    }
+  };
+  EXPECT_TRUE(
+      profiler_add_marker("Gtest custom marker", geckoprofiler::category::OTHER,
+                          MarkerTiming::Interval(ts1, ts2), GtestMarker{}, 42,
+                          43.0, "gtest text", "gtest unique text", ts1));
+
+  // User-defined marker type with no data, special frontend schema.
+  struct GtestSpecialMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-special");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+  EXPECT_TRUE(profiler_add_marker("Gtest special marker",
+                                  geckoprofiler::category::OTHER, {},
+                                  GtestSpecialMarker{}));
+
+  // User-defined marker type that is never used, so it shouldn't appear in the
+  // output.
+  struct GtestUnusedMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-unused");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+
+  // Make sure the compiler doesn't complain about this unused struct.
+  mozilla::Unused << GtestUnusedMarker{};
+
+  // Other markers in alphabetical order of payload class names.
+
+  nsCOMPtr<nsIURI> uri;
+  ASSERT_TRUE(
+      NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), "http://mozilla.org/"_ns)));
+  // The marker name will be "Load <aChannelId>: <aURI>".
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 1,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_START,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheHit,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      /* nsIURI* aRedirectURI = nullptr */
+      /* uint64_t aRedirectChannelId = 0 */
+  );
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 2,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_STOP,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      Some(nsDependentCString("text/html")),
+      /* nsIURI* aRedirectURI = nullptr */ nullptr,
+      /* uint64_t aRedirectChannelId = 0 */ 0);
+
+  nsCOMPtr<nsIURI> redirectURI;
+  ASSERT_TRUE(NS_SUCCEEDED(
+      NS_NewURI(getter_AddRefs(redirectURI), "http://example.com/"_ns)));
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 3,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */
+      nsIChannelEventSink::REDIRECT_TEMPORARY,
+      /* uint64_t aRedirectChannelId = 0 */ 103);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 4,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */
+      nsIChannelEventSink::REDIRECT_PERMANENT,
+      /* uint64_t aRedirectChannelId = 0 */ 104);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 5,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */ nsIChannelEventSink::REDIRECT_INTERNAL,
+      /* uint64_t aRedirectChannelId = 0 */ 105);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 6,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */ nsIChannelEventSink::REDIRECT_INTERNAL |
+          nsIChannelEventSink::REDIRECT_STS_UPGRADE,
+      /* uint64_t aRedirectChannelId = 0 */ 106);
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 7,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_START,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ true
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      /* nsIURI* aRedirectURI = nullptr */
+      /* uint64_t aRedirectChannelId = 0 */
+  );
+
+  EXPECT_TRUE(profiler_add_marker(
+      "Text in main thread with stack", geckoprofiler::category::OTHER,
+      {MarkerStack::Capture(), MarkerTiming::Interval(ts1, ts2)},
+      geckoprofiler::markers::TextMarker{}, ""));
+  EXPECT_TRUE(profiler_add_marker(
+      "Text from main thread with stack", geckoprofiler::category::OTHER,
+      MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+      geckoprofiler::markers::TextMarker{}, ""));
+
+  std::thread registeredThread([]() {
+    AUTO_PROFILER_REGISTER_THREAD("Marker test sub-thread");
+    // Marker in non-profiled thread won't be stored.
+    EXPECT_FALSE(profiler_add_marker(
+        "Text in registered thread with stack", geckoprofiler::category::OTHER,
+        MarkerStack::Capture(), geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, with stack from registered thread.
+    EXPECT_TRUE(profiler_add_marker(
+        "Text from registered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  registeredThread.join();
+
+  std::thread unregisteredThread([]() {
+    // Marker in unregistered thread won't be stored.
+    EXPECT_FALSE(profiler_add_marker("Text in unregistered thread with stack",
+                                     geckoprofiler::category::OTHER,
+                                     MarkerStack::Capture(),
+                                     geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, but stack cannot be captured in an
+    // unregistered thread.
+    EXPECT_TRUE(profiler_add_marker(
+        "Text from unregistered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  unregisteredThread.join();
+
+  EXPECT_TRUE(profiler_add_marker("Tracing", geckoprofiler::category::OTHER, {},
+                                  geckoprofiler::markers::Tracing{},
+                                  "category"));
+
+  EXPECT_TRUE(profiler_add_marker("Text", geckoprofiler::category::OTHER, {},
+                                  geckoprofiler::markers::TextMarker{},
+                                  "Text text"));
+
+  EXPECT_TRUE(profiler_add_marker(
+      "MediaSample", geckoprofiler::category::OTHER, {},
+      geckoprofiler::markers::MediaSampleMarker{}, 123, 456, 789));
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  w.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w));
+  w.End();
+
+  EXPECT_FALSE(w.Failed());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile.get());
+
+  // Expected markers, in order.
+  enum State {
+    S_tracing_event,
+    S_tracing_start,
+    S_tracing_end,
+    S_tracing_event_with_stack,
+    S_tracing_auto_tracing_start,
+    S_tracing_auto_tracing_end,
+    S_M1,
+    S_M3,
+    S_Markers2DefaultEmptyOptions,
+    S_Markers2DefaultWithOptions,
+    S_Markers2ExplicitDefaultEmptyOptions,
+    S_Markers2ExplicitDefaultWithOptions,
+    S_FirstMarker,
+    S_CustomMarker,
+    S_SpecialMarker,
+    S_NetworkMarkerPayload_start,
+    S_NetworkMarkerPayload_stop,
+    S_NetworkMarkerPayload_redirect_temporary,
+    S_NetworkMarkerPayload_redirect_permanent,
+    S_NetworkMarkerPayload_redirect_internal,
+    S_NetworkMarkerPayload_redirect_internal_sts,
+    S_NetworkMarkerPayload_private_browsing,
+
+    S_TextWithStack,
+    S_TextToMTWithStack,
+    S_RegThread_TextToMTWithStack,
+    S_UnregThread_TextToMTWithStack,
+
+    S_LAST,
+  } state = State(0);
+
+  // These will be set when first read from S_FirstMarker, then
+  // compared in following markers.
+  // TODO: Compute these values from the timestamps.
+  double ts1Double = 0.0;
+  double ts2Double = 0.0;
+
+  JSONOutputCheck(profile.get(), [&](const Json::Value& root) {
+    {
+      GET_JSON(threads, root["threads"], Array);
+      ASSERT_EQ(threads.size(), 1u);
+
+      {
+        GET_JSON(thread0, threads[0], Object);
+
+        // Keep a reference to the string table in this block, it will be used
+        // below.
+        GET_JSON(stringTable, thread0["stringTable"], Array);
+        ASSERT_TRUE(stringTable.isArray());
+
+        // Test the expected labels in the string table.
+        bool foundEmpty = false;
+        bool foundOkstr1 = false;
+        bool foundOkstr2 = false;
+        const std::string okstr2Label = std::string("okstr2 ") + okstr2.get();
+        bool foundTooLong = false;
+        for (const auto& s : stringTable) {
+          ASSERT_TRUE(s.isString());
+          std::string sString = s.asString();
+          if (sString.empty()) {
+            EXPECT_FALSE(foundEmpty);
+            foundEmpty = true;
+          } else if (sString == okstr1.get()) {
+            EXPECT_FALSE(foundOkstr1);
+            foundOkstr1 = true;
+          } else if (sString == okstr2Label) {
+            EXPECT_FALSE(foundOkstr2);
+            foundOkstr2 = true;
+          } else if (sString == longstrCut.get()) {
+            EXPECT_FALSE(foundTooLong);
+            foundTooLong = true;
+          } else {
+            EXPECT_NE(sString, longstr.get());
+          }
+        }
+        EXPECT_TRUE(foundEmpty);
+        EXPECT_TRUE(foundOkstr1);
+        EXPECT_TRUE(foundOkstr2);
+        EXPECT_TRUE(foundTooLong);
+
+        {
+          GET_JSON(markers, thread0["markers"], Object);
+
+          {
+            GET_JSON(data, markers["data"], Array);
+
+            for (const Json::Value& marker : data) {
+              // Name the indexes into the marker tuple:
+              // [name, startTime, endTime, phase, category, payload]
+              const unsigned int NAME = 0u;
+              const unsigned int START_TIME = 1u;
+              const unsigned int END_TIME = 2u;
+              const unsigned int PHASE = 3u;
+              const unsigned int CATEGORY = 4u;
+              const unsigned int PAYLOAD = 5u;
+
+              const unsigned int PHASE_INSTANT = 0;
+              const unsigned int PHASE_INTERVAL = 1;
+              const unsigned int PHASE_START = 2;
+              const unsigned int PHASE_END = 3;
+
+              const unsigned int SIZE_WITHOUT_PAYLOAD = 5u;
+              const unsigned int SIZE_WITH_PAYLOAD = 6u;
+
+              ASSERT_TRUE(marker.isArray());
+              // The payload is optional.
+              ASSERT_GE(marker.size(), SIZE_WITHOUT_PAYLOAD);
+              ASSERT_LE(marker.size(), SIZE_WITH_PAYLOAD);
+
+              // root.threads[0].markers.data[i] is an array with 5 or 6
+              // elements.
+
+              ASSERT_TRUE(marker[NAME].isUInt());  // name id
+              GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+              std::string nameString = name.asString();
+
+              EXPECT_TRUE(marker[START_TIME].isNumeric());
+              EXPECT_TRUE(marker[END_TIME].isNumeric());
+              EXPECT_TRUE(marker[PHASE].isUInt());
+              EXPECT_TRUE(marker[PHASE].asUInt() < 4);
+              EXPECT_TRUE(marker[CATEGORY].isUInt());
+
+#  define EXPECT_TIMING_INSTANT                  \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#  define EXPECT_TIMING_INTERVAL                 \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#  define EXPECT_TIMING_START                    \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#  define EXPECT_TIMING_END                      \
+    EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+    EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+#  define EXPECT_TIMING_INSTANT_AT(t)            \
+    EXPECT_EQ(marker[START_TIME].asDouble(), t); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#  define EXPECT_TIMING_INTERVAL_AT(start, end)      \
+    EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), end);     \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#  define EXPECT_TIMING_START_AT(start)              \
+    EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);       \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#  define EXPECT_TIMING_END_AT(end)              \
+    EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), end); \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+              if (marker.size() == SIZE_WITHOUT_PAYLOAD) {
+                // root.threads[0].markers.data[i] is an array with 5 elements,
+                // so there is no payload.
+                if (nameString == "M1") {
+                  ASSERT_EQ(state, S_M1);
+                  state = State(state + 1);
+                } else if (nameString == "M3") {
+                  ASSERT_EQ(state, S_M3);
+                  state = State(state + 1);
+                } else if (nameString ==
+                           "default-templated markers 2.0 with empty options") {
+                  EXPECT_EQ(state, S_Markers2DefaultEmptyOptions);
+                  state = State(S_Markers2DefaultEmptyOptions + 1);
+// TODO: Re-enable this when bug 1646714 lands, and check for stack.
+#  if 0
+              } else if (nameString ==
+                         "default-templated markers 2.0 with option") {
+                EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                state = State(S_Markers2DefaultWithOptions + 1);
+#  endif
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "empty "
+                           "options") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultEmptyOptions);
+                  state = State(S_Markers2ExplicitDefaultEmptyOptions + 1);
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "option") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultWithOptions);
+                  state = State(S_Markers2ExplicitDefaultWithOptions + 1);
+                }
+              } else {
+                // root.threads[0].markers.data[i] is an array with 6 elements,
+                // so there is a payload.
+                GET_JSON(payload, marker[PAYLOAD], Object);
+
+                // root.threads[0].markers.data[i][PAYLOAD] is an object
+                // (payload).
+
+                // It should at least have a "type" string.
+                GET_JSON(type, payload["type"], String);
+                std::string typeString = type.asString();
+
+                if (nameString == "tracing event") {
+                  EXPECT_EQ(state, S_tracing_event);
+                  state = State(S_tracing_event + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing start") {
+                  EXPECT_EQ(state, S_tracing_start);
+                  state = State(S_tracing_start + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_START;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing end") {
+                  EXPECT_EQ(state, S_tracing_end);
+                  state = State(S_tracing_end + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_END;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing event with stack") {
+                  EXPECT_EQ(state, S_tracing_event_with_stack);
+                  state = State(S_tracing_event_with_stack + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "B");
+                  EXPECT_TRUE(payload["stack"].isObject());
+
+                } else if (nameString == "auto tracing") {
+                  switch (state) {
+                    case S_tracing_auto_tracing_start:
+                      state = State(S_tracing_auto_tracing_start + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_START;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      EXPECT_TRUE(payload["stack"].isNull());
+                      break;
+                    case S_tracing_auto_tracing_end:
+                      state = State(S_tracing_auto_tracing_end + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_END;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      ASSERT_TRUE(payload["stack"].isNull());
+                      break;
+                    default:
+                      EXPECT_TRUE(state == S_tracing_auto_tracing_start ||
+                                  state == S_tracing_auto_tracing_end);
+                      break;
+                  }
+
+                } else if (nameString ==
+                           "default-templated markers 2.0 with option") {
+                  // TODO: Remove this when bug 1646714 lands.
+                  EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                  state = State(S_Markers2DefaultWithOptions + 1);
+                  EXPECT_EQ(typeString, "NoPayloadUserData");
+                  EXPECT_FALSE(payload["stack"].isNull());
+
+                } else if (nameString == "FirstMarker") {
+                  // Record start and end times, to compare with timestamps in
+                  // following markers.
+                  EXPECT_EQ(state, S_FirstMarker);
+                  ts1Double = marker[START_TIME].asDouble();
+                  ts2Double = marker[END_TIME].asDouble();
+                  state = State(S_FirstMarker + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_EQ_JSON(payload["name"], String, "First Marker");
+
+                } else if (nameString == "Gtest custom marker") {
+                  EXPECT_EQ(state, S_CustomMarker);
+                  state = State(S_CustomMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest");
+                  EXPECT_EQ(payload.size(), 1u + 9u);
+                  EXPECT_TRUE(payload["null"].isNull());
+                  EXPECT_EQ_JSON(payload["bool-false"], Bool, false);
+                  EXPECT_EQ_JSON(payload["bool-true"], Bool, true);
+                  EXPECT_EQ_JSON(payload["int"], Int64, 42);
+                  EXPECT_EQ_JSON(payload["double"], Double, 43.0);
+                  EXPECT_EQ_JSON(payload["text"], String, "gtest text");
+                  // Unique strings can be fetched from the string table.
+                  ASSERT_TRUE(payload["unique text"].isUInt());
+                  auto textIndex = payload["unique text"].asUInt();
+                  GET_JSON(uniqueText, stringTable[textIndex], String);
+                  ASSERT_TRUE(uniqueText.isString());
+                  ASSERT_EQ(uniqueText.asString(), "gtest unique text");
+                  // The duplicate unique text should have the exact same index.
+                  EXPECT_EQ_JSON(payload["unique text again"], UInt, textIndex);
+                  EXPECT_EQ_JSON(payload["time"], Double, ts1Double);
+
+                } else if (nameString == "Gtest special marker") {
+                  EXPECT_EQ(state, S_SpecialMarker);
+                  state = State(S_SpecialMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest-special");
+                  EXPECT_EQ(payload.size(), 1u) << "Only 'type' in the payload";
+
+                } else if (nameString == "Load 1: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_start);
+                  state = State(S_NetworkMarkerPayload_start + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 1);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Hit");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 2: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_stop);
+                  state = State(S_NetworkMarkerPayload_stop + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 2);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_EQ_JSON(payload["contentType"], String, "text/html");
+
+                } else if (nameString == "Load 3: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_temporary);
+                  state = State(S_NetworkMarkerPayload_redirect_temporary + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 3);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Temporary");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 103);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 4: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_permanent);
+                  state = State(S_NetworkMarkerPayload_redirect_permanent + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 4);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Permanent");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 104);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 5: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_internal);
+                  state = State(S_NetworkMarkerPayload_redirect_internal + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 5);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Internal");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 105);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 6: http://mozilla.org/") {
+                  EXPECT_EQ(state,
+                            S_NetworkMarkerPayload_redirect_internal_sts);
+                  state =
+                      State(S_NetworkMarkerPayload_redirect_internal_sts + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 6);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Internal");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, true);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 106);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 7: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_private_browsing);
+                  state = State(S_NetworkMarkerPayload_private_browsing + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 7);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_EQ_JSON(payload["isPrivateBrowsing"], Bool, true);
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_TRUE(payload["contentType"].isNull());
+                } else if (nameString == "Text in main thread with stack") {
+                  EXPECT_EQ(state, S_TextWithStack);
+                  state = State(S_TextWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_TIMING_INTERVAL_AT(ts1Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString == "Text from main thread with stack") {
+                  EXPECT_EQ(state, S_TextToMTWithStack);
+                  state = State(S_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in registered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in registered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from registered thread with stack") {
+                  EXPECT_EQ(state, S_RegThread_TextToMTWithStack);
+                  state = State(S_RegThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in unregistered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in unregistered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from unregistered thread with stack") {
+                  EXPECT_EQ(state, S_UnregThread_TextToMTWithStack);
+                  state = State(S_UnregThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_TRUE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+                }
+              }  // marker with payload
+            }    // for (marker : data)
+          }      // markers.data
+        }        // markers
+      }          // thread0
+    }            // threads
+    // We should have read all expected markers.
+    EXPECT_EQ(state, S_LAST);
+
+    {
+      GET_JSON(meta, root["meta"], Object);
+
+      {
+        GET_JSON(markerSchema, meta["markerSchema"], Array);
+
+        std::set<std::string> testedSchemaNames;
+
+        for (const Json::Value& schema : markerSchema) {
+          GET_JSON(name, schema["name"], String);
+          const std::string nameString = name.asString();
+
+          GET_JSON(display, schema["display"], Array);
+
+          GET_JSON(data, schema["data"], Array);
+
+          EXPECT_TRUE(
+              testedSchemaNames
+                  .insert(std::string(nameString.data(), nameString.size()))
+                  .second)
+              << "Each schema name should be unique (inserted once in the set)";
+
+          if (nameString == "Text") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Details");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "NoPayloadUserData") {
+            // TODO: Remove this when bug 1646714 lands.
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "FileIO") {
+            // These are defined in ProfilerIOInterposeObserver.cpp
+
+          } else if (nameString == "tracing") {
+            EXPECT_EQ(display.size(), 3u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "BHR-detected hang") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "MainThreadLongTask") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "Log") {
+            EXPECT_EQ(display.size(), 1u);
+            EXPECT_EQ(display[0u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "module");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Module");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Name");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "string");
+
+          } else if (nameString == "MediaSample") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 3u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "sampleStartTimeUs");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Sample start time");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "sampleEndTimeUs");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Sample end time");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[2u].isObject());
+            EXPECT_EQ_JSON(data[2u]["key"], String, "queueLength");
+            EXPECT_EQ_JSON(data[2u]["label"], String, "Queue length");
+            EXPECT_EQ_JSON(data[2u]["format"], String, "integer");
+
+          } else if (nameString == "VideoFallingBehind") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "videoFrameStartTimeUs");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Video frame start time");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "mediaCurrentTimeUs");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Media current time");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "microseconds");
+
+          } else if (nameString == "Budget") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest") {
+            EXPECT_EQ(display.size(), 7u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+            EXPECT_EQ(display[3u].asString(), "timeline-memory");
+            EXPECT_EQ(display[4u].asString(), "timeline-ipc");
+            EXPECT_EQ(display[5u].asString(), "timeline-fileio");
+            EXPECT_EQ(display[6u].asString(), "stack-chart");
+
+            EXPECT_EQ_JSON(schema["chartLabel"], String, "chart label");
+            EXPECT_EQ_JSON(schema["tooltipLabel"], String, "tooltip label");
+            EXPECT_EQ_JSON(schema["tableLabel"], String, "table label");
+
+            ASSERT_EQ(data.size(), 14u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "key with url");
+            EXPECT_TRUE(data[0u]["label"].isNull());
+            EXPECT_EQ_JSON(data[0u]["format"], String, "url");
+            EXPECT_TRUE(data[0u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "key with label filePath");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "label filePath");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "file-path");
+            EXPECT_TRUE(data[1u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[2u].isObject());
+            EXPECT_EQ_JSON(data[2u]["key"], String,
+                           "key with string not-searchable");
+            EXPECT_TRUE(data[2u]["label"].isNull());
+            EXPECT_EQ_JSON(data[2u]["format"], String, "string");
+            EXPECT_EQ_JSON(data[2u]["searchable"], Bool, false);
+
+            ASSERT_TRUE(data[3u].isObject());
+            EXPECT_EQ_JSON(data[3u]["key"], String,
+                           "key with label duration searchable");
+            EXPECT_TRUE(data[3u]["label duration"].isNull());
+            EXPECT_EQ_JSON(data[3u]["format"], String, "duration");
+            EXPECT_EQ_JSON(data[3u]["searchable"], Bool, true);
+
+            ASSERT_TRUE(data[4u].isObject());
+            EXPECT_EQ_JSON(data[4u]["key"], String, "key with time");
+            EXPECT_TRUE(data[4u]["label"].isNull());
+            EXPECT_EQ_JSON(data[4u]["format"], String, "time");
+            EXPECT_TRUE(data[4u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[5u].isObject());
+            EXPECT_EQ_JSON(data[5u]["key"], String, "key with seconds");
+            EXPECT_TRUE(data[5u]["label"].isNull());
+            EXPECT_EQ_JSON(data[5u]["format"], String, "seconds");
+            EXPECT_TRUE(data[5u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[6u].isObject());
+            EXPECT_EQ_JSON(data[6u]["key"], String, "key with milliseconds");
+            EXPECT_TRUE(data[6u]["label"].isNull());
+            EXPECT_EQ_JSON(data[6u]["format"], String, "milliseconds");
+            EXPECT_TRUE(data[6u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[7u].isObject());
+            EXPECT_EQ_JSON(data[7u]["key"], String, "key with microseconds");
+            EXPECT_TRUE(data[7u]["label"].isNull());
+            EXPECT_EQ_JSON(data[7u]["format"], String, "microseconds");
+            EXPECT_TRUE(data[7u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[8u].isObject());
+            EXPECT_EQ_JSON(data[8u]["key"], String, "key with nanoseconds");
+            EXPECT_TRUE(data[8u]["label"].isNull());
+            EXPECT_EQ_JSON(data[8u]["format"], String, "nanoseconds");
+            EXPECT_TRUE(data[8u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[9u].isObject());
+            EXPECT_EQ_JSON(data[9u]["key"], String, "key with bytes");
+            EXPECT_TRUE(data[9u]["label"].isNull());
+            EXPECT_EQ_JSON(data[9u]["format"], String, "bytes");
+            EXPECT_TRUE(data[9u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[10u].isObject());
+            EXPECT_EQ_JSON(data[10u]["key"], String, "key with percentage");
+            EXPECT_TRUE(data[10u]["label"].isNull());
+            EXPECT_EQ_JSON(data[10u]["format"], String, "percentage");
+            EXPECT_TRUE(data[10u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[11u].isObject());
+            EXPECT_EQ_JSON(data[11u]["key"], String, "key with integer");
+            EXPECT_TRUE(data[11u]["label"].isNull());
+            EXPECT_EQ_JSON(data[11u]["format"], String, "integer");
+            EXPECT_TRUE(data[11u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[12u].isObject());
+            EXPECT_EQ_JSON(data[12u]["key"], String, "key with decimal");
+            EXPECT_TRUE(data[12u]["label"].isNull());
+            EXPECT_EQ_JSON(data[12u]["format"], String, "decimal");
+            EXPECT_TRUE(data[12u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[13u].isObject());
+            EXPECT_EQ_JSON(data[13u]["label"], String, "static label");
+            EXPECT_EQ_JSON(data[13u]["value"], String, "static value");
+
+          } else if (nameString == "markers-gtest-special") {
+            EXPECT_EQ(display.size(), 0u);
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest-unused") {
+            ADD_FAILURE() << "Schema for GtestUnusedMarker should not be here";
+
+          } else {
+            printf("FYI: Unknown marker schema '%s'\n", nameString.c_str());
+          }
+        }
+
+        // Check that we've got all expected schema.
+        EXPECT_TRUE(testedSchemaNames.find("Text") != testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("tracing") !=
+                    testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("MediaSample") !=
+                    testedSchemaNames.end());
+      }  // markerSchema
+    }    // meta
+  });
+
+  Maybe<ProfilerBufferInfo> info = profiler_get_buffer_info();
+  EXPECT_TRUE(info.isSome());
+  printf("Profiler buffer range: %llu .. %llu (%llu bytes)\n",
+         static_cast<unsigned long long>(info->mRangeStart),
+         static_cast<unsigned long long>(info->mRangeEnd),
+         // sizeof(ProfileBufferEntry) == 9
+         (static_cast<unsigned long long>(info->mRangeEnd) -
+          static_cast<unsigned long long>(info->mRangeStart)) *
+             9);
+  printf("Stats:         min(us) .. mean(us) .. max(us)  [count]\n");
+  printf("- Intervals:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mIntervalsUs.min, info->mIntervalsUs.sum / info->mIntervalsUs.n,
+         info->mIntervalsUs.max, info->mIntervalsUs.n);
+  printf("- Overheads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mOverheadsUs.min, info->mOverheadsUs.sum / info->mOverheadsUs.n,
+         info->mOverheadsUs.max, info->mOverheadsUs.n);
+  printf("  - Locking:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mLockingsUs.min, info->mLockingsUs.sum / info->mLockingsUs.n,
+         info->mLockingsUs.max, info->mLockingsUs.n);
+  printf("  - Clearning: %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCleaningsUs.min, info->mCleaningsUs.sum / info->mCleaningsUs.n,
+         info->mCleaningsUs.max, info->mCleaningsUs.n);
+  printf("  - Counters:  %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCountersUs.min, info->mCountersUs.sum / info->mCountersUs.n,
+         info->mCountersUs.max, info->mCountersUs.n);
+  printf("  - Threads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mThreadsUs.min, info->mThreadsUs.sum / info->mThreadsUs.n,
+         info->mThreadsUs.max, info->mThreadsUs.n);
+
+  profiler_stop();
+
+  // Try to add markers while the profiler is stopped.
+  PROFILER_MARKER_UNTYPED("marker after profiler_stop", OTHER);
+
+  // Warning: this could be racy
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // This last marker shouldn't get streamed.
+  SpliceableChunkedJSONWriter w2{FailureLatchInfallibleSource::Singleton()};
+  w2.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w2));
+  w2.End();
+  EXPECT_FALSE(w2.Failed());
+  UniquePtr<char[]> profile2 = w2.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile2.get());
+  EXPECT_TRUE(
+      std::string_view(profile2.get()).find("marker after profiler_stop") ==
+      std::string_view::npos);
+
+  profiler_stop();
+}
+
+#  define COUNTER_NAME "TestCounter"
+#  define COUNTER_DESCRIPTION "Test of counters in profiles"
+#  define COUNTER_NAME2 "Counter2"
+#  define COUNTER_DESCRIPTION2 "Second Test of counters in profiles"
+
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter, COUNTER_NAME, COUNTER_DESCRIPTION);
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter2, COUNTER_NAME2, COUNTER_DESCRIPTION2);
+
+TEST(GeckoProfiler, Counters)
+{
+  uint32_t features = 0;
+  const char* filters[] = {"GeckoMain"};
+
+  // We will record some counter values, and check that they're present (and no
+  // other) when expected.
+
+  struct NumberAndCount {
+    uint64_t mNumber;
+    int64_t mCount;
+  };
+
+  int64_t testCounters[] = {10, 7, -17};
+  NumberAndCount expectedTestCounters[] = {{1u, 10}, {0u, 0}, {1u, 7},
+                                           {0u, 0},  {0u, 0}, {1u, -17},
+                                           {0u, 0},  {0u, 0}};
+  constexpr size_t expectedTestCountersCount =
+      MOZ_ARRAY_LENGTH(expectedTestCounters);
+
+  bool expectCounter2 = false;
+  int64_t testCounters2[] = {10};
+  NumberAndCount expectedTestCounters2[] = {{1u, 10}, {0u, 0}};
+  constexpr size_t expectedTestCounters2Count =
+      MOZ_ARRAY_LENGTH(expectedTestCounters2);
+
+  auto checkCountersInJSON = [&](const Json::Value& aRoot) {
+    size_t nextExpectedTestCounter = 0u;
+    size_t nextExpectedTestCounter2 = 0u;
+
+    GET_JSON(counters, aRoot["counters"], Array);
+    for (const Json::Value& counter : counters) {
+      ASSERT_TRUE(counter.isObject());
+      GET_JSON_VALUE(name, counter["name"], String);
+      if (name == "TestCounter") {
+        EXPECT_EQ_JSON(counter["category"], String, COUNTER_NAME);
+        EXPECT_EQ_JSON(counter["description"], String, COUNTER_DESCRIPTION);
+        GET_JSON(sampleGroups, counter["sample_groups"], Array);
+        for (const Json::Value& sampleGroup : sampleGroups) {
+          ASSERT_TRUE(sampleGroup.isObject());
+          EXPECT_EQ_JSON(sampleGroup["id"], UInt, 0u);
+
+          GET_JSON(samples, sampleGroup["samples"], Object);
+          GET_JSON(samplesSchema, samples["schema"], Object);
+          EXPECT_GE(samplesSchema.size(), 3u);
+          GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+          GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+          GET_JSON(samplesData, samples["data"], Array);
+          for (const Json::Value& sample : samplesData) {
+            ASSERT_TRUE(sample.isArray());
+            ASSERT_LT(nextExpectedTestCounter, expectedTestCountersCount);
+            EXPECT_EQ_JSON(
+                sample[samplesNumber], UInt64,
+                expectedTestCounters[nextExpectedTestCounter].mNumber);
+            EXPECT_EQ_JSON(
+                sample[samplesCount], Int64,
+                expectedTestCounters[nextExpectedTestCounter].mCount);
+            ++nextExpectedTestCounter;
+          }
+        }
+      } else if (name == "TestCounter2") {
+        EXPECT_TRUE(expectCounter2);
+
+        EXPECT_EQ_JSON(counter["category"], String, COUNTER_NAME2);
+        EXPECT_EQ_JSON(counter["description"], String, COUNTER_DESCRIPTION2);
+        GET_JSON(sampleGroups, counter["sample_groups"], Array);
+        for (const Json::Value& sampleGroup : sampleGroups) {
+          ASSERT_TRUE(sampleGroup.isObject());
+          EXPECT_EQ_JSON(sampleGroup["id"], UInt, 0u);
+
+          GET_JSON(samples, sampleGroup["samples"], Object);
+          GET_JSON(samplesSchema, samples["schema"], Object);
+          EXPECT_GE(samplesSchema.size(), 3u);
+          GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+          GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+          GET_JSON(samplesData, samples["data"], Array);
+          for (const Json::Value& sample : samplesData) {
+            ASSERT_TRUE(sample.isArray());
+            ASSERT_LT(nextExpectedTestCounter2, expectedTestCounters2Count);
+            EXPECT_EQ_JSON(
+                sample[samplesNumber], UInt64,
+                expectedTestCounters2[nextExpectedTestCounter2].mNumber);
+            EXPECT_EQ_JSON(
+                sample[samplesCount], Int64,
+                expectedTestCounters2[nextExpectedTestCounter2].mCount);
+            ++nextExpectedTestCounter2;
+          }
+        }
+      }
+    }
+
+    EXPECT_EQ(nextExpectedTestCounter, expectedTestCountersCount);
+    if (expectCounter2) {
+      EXPECT_EQ(nextExpectedTestCounter2, expectedTestCounters2Count);
+    }
+  };
+
+  // Inactive -> Active
+  profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                          features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Output all "TestCounter"s, with increasing delays (to test different
+  // number of counter samplings).
+  int samplingWaits = 2;
+  for (int64_t counter : testCounters) {
+    AUTO_PROFILER_COUNT_TOTAL(TestCounter, counter);
+    for (int i = 0; i < samplingWaits; ++i) {
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+    ++samplingWaits;
+  }
+
+  // Verify we got "TestCounter" in the output, but not "TestCounter2" yet.
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), checkCountersInJSON);
+
+  // Now introduce TestCounter2.
+  expectCounter2 = true;
+  for (int64_t counter2 : testCounters2) {
+    AUTO_PROFILER_COUNT_TOTAL(TestCounter2, counter2);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+
+  // Verify we got both "TestCounter" and "TestCounter2" in the output.
+  profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), checkCountersInJSON);
+
+  profiler_stop();
+}
+
+TEST(GeckoProfiler, Time)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  double t1 = profiler_time();
+  double t2 = profiler_time();
+  ASSERT_TRUE(t1 <= t2);
+
+  // profiler_start() restarts the timer used by profiler_time().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  double t3 = profiler_time();
+  double t4 = profiler_time();
+  ASSERT_TRUE(t3 <= t4);
+
+  profiler_stop();
+
+  double t5 = profiler_time();
+  double t6 = profiler_time();
+  ASSERT_TRUE(t4 <= t5 && t1 <= t6);
+}
+
+TEST(GeckoProfiler, GetProfile)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_get_profile());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  mozilla::Maybe<uint32_t> activeFeatures = profiler_features_if_active();
+  ASSERT_TRUE(activeFeatures.isSome());
+  // Not all platforms support stack-walking.
+  const bool hasStackWalk = ProfilerFeature::HasStackWalk(*activeFeatures);
+
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+    GET_JSON(meta, aRoot["meta"], Object);
+    {
+      GET_JSON(configuration, meta["configuration"], Object);
+      {
+        GET_JSON(features, configuration["features"], Array);
+        {
+          EXPECT_EQ(features.size(), (hasStackWalk ? 1u : 0u));
+          if (hasStackWalk) {
+            EXPECT_JSON_ARRAY_CONTAINS(features, String, "stackwalk");
+          }
+        }
+        GET_JSON(threads, configuration["threads"], Array);
+        {
+          EXPECT_EQ(threads.size(), 1u);
+          EXPECT_JSON_ARRAY_CONTAINS(threads, String, "GeckoMain");
+        }
+      }
+    }
+  });
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, StreamJSONForThisProcess)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Fallible());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(&w.ChunkedWriteFunc().SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(
+      &std::as_const(w.ChunkedWriteFunc()).SourceFailureLatch() ==
+      &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(!w.Fallible());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+  MOZ_RELEASE_ASSERT(&w.SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(&std::as_const(w).SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  w.Start();
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w));
+  w.End();
+
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  profiler_stop();
+
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+}
+
+// Internal version of profiler_stream_json_for_this_process, which allows being
+// called from a non-main thread of the parent process, at the risk of getting
+// an incomplete profile.
+bool do_profiler_stream_json_for_this_process(
+    SpliceableJSONWriter& aWriter, double aSinceTime, bool aIsShuttingDown,
+    ProfilerCodeAddressService* aService,
+    mozilla::ProgressLogger aProgressLogger);
+
+TEST(GeckoProfiler, StreamJSONForThisProcessThreaded)
+{
+  // Same as the previous test, but calling some things on background threads.
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Fallible());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(&w.ChunkedWriteFunc().SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(
+      &std::as_const(w.ChunkedWriteFunc()).SourceFailureLatch() ==
+      &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(!w.Fallible());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+  MOZ_RELEASE_ASSERT(&w.SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(&std::as_const(w).SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  // Start the profiler on the main thread.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Call profiler_stream_json_for_this_process on a background thread.
+  thread->Dispatch(
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            w.Start();
+            ASSERT_TRUE(::do_profiler_stream_json_for_this_process(
+                w, /* double aSinceTime */ 0.0,
+                /* bool aIsShuttingDown */ false,
+                /* ProfilerCodeAddressService* aService */ nullptr,
+                mozilla::ProgressLogger{}));
+            w.End();
+          }),
+      NS_DISPATCH_SYNC);
+
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  // Stop the profiler and call profiler_stream_json_for_this_process on a
+  // background thread.
+  thread->Dispatch(
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            profiler_stop();
+            ASSERT_TRUE(!::do_profiler_stream_json_for_this_process(
+                w, /* double aSinceTime */ 0.0,
+                /* bool aIsShuttingDown */ false,
+                /* ProfilerCodeAddressService* aService */ nullptr,
+                mozilla::ProgressLogger{}));
+          }),
+      NS_DISPATCH_SYNC);
+  thread->Shutdown();
+
+  // Call profiler_stream_json_for_this_process on the main thread.
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+}
+
+TEST(GeckoProfiler, ProfilingStack)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  AUTO_PROFILER_LABEL("A::B", OTHER);
+
+  UniqueFreePtr<char> dynamic(strdup("dynamic"));
+  {
+    AUTO_PROFILER_LABEL_DYNAMIC_CSTR("A::C", JS, dynamic.get());
+    AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("A::C2", JS,
+                                          nsDependentCString(dynamic.get()));
+    AUTO_PROFILER_LABEL_DYNAMIC_LOSSY_NSSTRING(
+        "A::C3", JS, NS_ConvertUTF8toUTF16(dynamic.get()));
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_get_backtrace());
+  }
+
+  AutoProfilerLabel label1("A", nullptr, JS::ProfilingCategoryPair::DOM);
+  AutoProfilerLabel label2("A", dynamic.get(),
+                           JS::ProfilingCategoryPair::NETWORK);
+  ASSERT_TRUE(profiler_get_backtrace());
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, Bug1355807)
+{
+  uint32_t features = ProfilerFeature::JS;
+  const char* manyThreadsFilter[] = {""};
+  const char* fewThreadsFilter[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 manyThreadsFilter, MOZ_ARRAY_LENGTH(manyThreadsFilter), 0);
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  // In bug 1355807 this caused an assertion failure in StopJSSampling().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  profiler_stop();
+}
+
+class GTestStackCollector final : public ProfilerStackCollector {
+ public:
+  GTestStackCollector() : mSetIsMainThread(0), mFrames(0) {}
+
+  virtual void SetIsMainThread() { mSetIsMainThread++; }
+
+  virtual void CollectNativeLeafAddr(void* aAddr) { mFrames++; }
+  virtual void CollectJitReturnAddr(void* aAddr) { mFrames++; }
+  virtual void CollectWasmFrame(const char* aLabel) { mFrames++; }
+  virtual void CollectProfilingStackFrame(
+      const js::ProfilingStackFrame& aFrame) {
+    mFrames++;
+  }
+
+  int mSetIsMainThread;
+  int mFrames;
+};
+
+void DoSuspendAndSample(ProfilerThreadId aTidToSample,
+                        nsIThread* aSamplingThread) {
+  aSamplingThread->Dispatch(
+      NS_NewRunnableFunction(
+          "GeckoProfiler_SuspendAndSample_Test::TestBody",
+          [&]() {
+            uint32_t features = ProfilerFeature::CPUUtilization;
+            GTestStackCollector collector;
+            profiler_suspend_and_sample_thread(aTidToSample, features,
+                                               collector,
+                                               /* sampleNative = */ true);
+
+            ASSERT_TRUE(collector.mSetIsMainThread ==
+                        (aTidToSample == profiler_main_thread_id()));
+            ASSERT_TRUE(collector.mFrames > 0);
+          }),
+      NS_DISPATCH_SYNC);
+}
+
+TEST(GeckoProfiler, SuspendAndSample)
+{
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  ProfilerThreadId tid = profiler_current_thread_id();
+
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Suspend and sample while the profiler is inactive.
+  DoSuspendAndSample(tid, thread);
+
+  DoSuspendAndSample(ProfilerThreadId{}, thread);
+
+  uint32_t features = ProfilerFeature::JS;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(profiler_is_active());
+
+  // Suspend and sample while the profiler is active.
+  DoSuspendAndSample(tid, thread);
+
+  DoSuspendAndSample(ProfilerThreadId{}, thread);
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_active());
+}
+
+TEST(GeckoProfiler, PostSamplingCallback)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileCompleted = profiler_get_profile();
+  JSONOutputCheck(profileCompleted.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback completed");
+      }
+    }
+  });
+
+  profiler_pause();
+  {
+    // Paused -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback paused", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingPaused);
+  }
+  UniquePtr<char[]> profilePaused = profiler_get_profile();
+  JSONOutputCheck(profilePaused.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profilePaused.get(), "PostSamplingCallback paused"));
+
+  profiler_resume();
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback resumed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileResumed = profiler_get_profile();
+  JSONOutputCheck(profileResumed.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback resumed");
+      }
+    }
+  });
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::NoStackSampling,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  {
+    // No stack sampling -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed (no stacks)", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::NoStackSamplingCompleted);
+  }
+  UniquePtr<char[]> profileNoStacks = profiler_get_profile();
+  JSONOutputCheck(profileNoStacks.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profileNoStacks.get(),
+                      "PostSamplingCallback completed (no stacks)"));
+
+  // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+  // it would require coordination between `profiler_stop()` and another thread
+  // doing `profiler_callback_after_sampling()` at just the right moment.
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+}
+
+TEST(GeckoProfiler, ProfilingStateCallback)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+
+  struct ProfilingStateAndId {
+    ProfilingState mProfilingState;
+    int mId;
+  };
+  DataMutex<Vector<ProfilingStateAndId>> states{"Profiling states"};
+  auto CreateCallback = [&states](int id) {
+    return [id, &states](ProfilingState aProfilingState) {
+      auto lockedStates = states.Lock();
+      ASSERT_TRUE(
+          lockedStates->append(ProfilingStateAndId{aProfilingState, id}));
+    };
+  };
+  auto CheckStatesIsEmpty = [&states]() {
+    auto lockedStates = states.Lock();
+    EXPECT_TRUE(lockedStates->empty());
+  };
+  auto CheckStatesOnlyContains = [&states](ProfilingState aProfilingState,
+                                           int aId) {
+    auto lockedStates = states.Lock();
+    EXPECT_EQ(lockedStates->length(), 1u);
+    if (lockedStates->length() >= 1u) {
+      EXPECT_EQ((*lockedStates)[0].mProfilingState, aProfilingState);
+      EXPECT_EQ((*lockedStates)[0].mId, aId);
+    }
+    lockedStates->clear();
+  };
+
+  profiler_add_state_change_callback(AllProfilingStates(), CreateCallback(1),
+                                     1);
+  // This is in case of error, and it also exercises the (allowed) removal of
+  // unknown callback ids.
+  auto cleanup1 = mozilla::MakeScopeExit(
+      []() { profiler_remove_state_change_callback(1); });
+  CheckStatesIsEmpty();
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+
+  CheckStatesOnlyContains(ProfilingState::Started, 1);
+
+  profiler_add_state_change_callback(AllProfilingStates(), CreateCallback(2),
+                                     2);
+  // This is in case of error, and it also exercises the (allowed) removal of
+  // unknown callback ids.
+  auto cleanup2 = mozilla::MakeScopeExit(
+      []() { profiler_remove_state_change_callback(2); });
+  CheckStatesOnlyContains(ProfilingState::AlreadyActive, 2);
+
+  profiler_remove_state_change_callback(2);
+  CheckStatesOnlyContains(ProfilingState::RemovingCallback, 2);
+  // Note: The actual removal is effectively tested below, by not seeing any
+  // more invocations of the 2nd callback.
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  UniquePtr<char[]> profileCompleted = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileCompleted.get(), [](const Json::Value& aRoot) {});
+
+  profiler_pause();
+  CheckStatesOnlyContains(ProfilingState::Pausing, 1);
+  UniquePtr<char[]> profilePaused = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profilePaused.get(), [](const Json::Value& aRoot) {});
+
+  profiler_resume();
+  CheckStatesOnlyContains(ProfilingState::Resumed, 1);
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  UniquePtr<char[]> profileResumed = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileResumed.get(), [](const Json::Value& aRoot) {});
+
+  // This effectively stops the profiler before restarting it, but
+  // ProfilingState::Stopping is not notified. See `profiler_start` for details.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::NoStackSampling,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  CheckStatesOnlyContains(ProfilingState::Started, 1);
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::NoStackSamplingCompleted);
+  UniquePtr<char[]> profileNoStacks = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileNoStacks.get(), [](const Json::Value& aRoot) {});
+
+  profiler_stop();
+  CheckStatesOnlyContains(ProfilingState::Stopping, 1);
+  ASSERT_TRUE(!profiler_is_active());
+
+  profiler_remove_state_change_callback(1);
+  CheckStatesOnlyContains(ProfilingState::RemovingCallback, 1);
+
+  // Note: ProfilingState::ShuttingDown cannot be tested here, and the profiler
+  // can only be shut down once per process.
+}
+
+TEST(GeckoProfiler, BaseProfilerHandOff)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker before base profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker before base profiler", OTHER, {});
+
+  // Start the Base Profiler.
+  baseprofiler::profiler_start(
+      PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+      ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters));
+
+  ASSERT_TRUE(baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Add at least a marker, which should go straight into the buffer.
+  Maybe<baseprofiler::ProfilerBufferInfo> info0 =
+      baseprofiler::profiler_get_buffer_info();
+  BASE_PROFILER_MARKER_UNTYPED("Base marker during base profiler", OTHER, {});
+  Maybe<baseprofiler::ProfilerBufferInfo> info1 =
+      baseprofiler::profiler_get_buffer_info();
+  ASSERT_GT(info1->mRangeEnd, info0->mRangeEnd);
+
+  PROFILER_MARKER_UNTYPED("Gecko marker during base profiler", OTHER, {});
+
+  // Start the Gecko Profiler, which should grab the Base Profiler profile and
+  // stop it.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker during gecko profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker during gecko profiler", OTHER, {});
+
+  // Write some Gecko Profiler samples.
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+  // Check that the Gecko Profiler profile contains at least the Base Profiler
+  // main thread samples.
+  UniquePtr<char[]> profile = profiler_get_profile();
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker after gecko profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker after gecko profiler", OTHER, {});
+
+  JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      bool found = false;
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          found = true;
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Base marker before base profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker before base profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Base marker during base profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker during base profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Base marker during gecko profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Gecko marker during gecko profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Base marker after gecko profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker after gecko profiler");
+          break;
+        }
+      }
+      EXPECT_TRUE(found);
+    }
+  });
+}
+
+static std::string_view GetFeatureName(uint32_t feature) {
+  switch (feature) {
+#  define FEATURE_NAME(n_, str_, Name_, desc_) \
+    case ProfilerFeature::Name_:               \
+      return str_;
+
+    PROFILER_FOR_EACH_FEATURE(FEATURE_NAME)
+
+#  undef FEATURE_NAME
+
+    default:
+      return "?";
+  }
+}
+
+TEST(GeckoProfiler, FeatureCombinations)
+{
+  const char* filters[] = {"*"};
+
+  // List of features to test. Every combination of up to 3 of them will be
+  // tested, so be careful not to add too many to keep the test run at a
+  // reasonable time.
+  uint32_t featureList[] = {ProfilerFeature::JS,
+                            ProfilerFeature::Screenshots,
+                            ProfilerFeature::StackWalk,
+                            ProfilerFeature::NoStackSampling,
+                            ProfilerFeature::NativeAllocations,
+                            ProfilerFeature::CPUUtilization,
+                            ProfilerFeature::CPUAllThreads,
+                            ProfilerFeature::SamplingAllThreads,
+                            ProfilerFeature::MarkersAllThreads,
+                            ProfilerFeature::UnregisteredThreads};
+  constexpr uint32_t featureCount = uint32_t(MOZ_ARRAY_LENGTH(featureList));
+
+  auto testFeatures = [&](uint32_t features,
+                          const std::string& featuresString) {
+    SCOPED_TRACE(featuresString.c_str());
+
+    ASSERT_TRUE(!profiler_is_active());
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_is_active());
+
+    // Write some Gecko Profiler samples.
+    EXPECT_EQ(WaitForSamplingState(),
+              (((features & ProfilerFeature::NoStackSampling) != 0) &&
+               ((features & (ProfilerFeature::CPUUtilization |
+                             ProfilerFeature::CPUAllThreads)) == 0))
+                  ? SamplingState::NoStackSamplingCompleted
+                  : SamplingState::SamplingCompleted);
+
+    // Check that the profile looks valid. Note that we don't test feature-
+    // specific changes.
+    UniquePtr<char[]> profile = profiler_get_profile();
+    JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {});
+
+    profiler_stop();
+    ASSERT_TRUE(!profiler_is_active());
+  };
+
+  testFeatures(0, "Features: (none)");
+
+  for (uint32_t f1 = 0u; f1 < featureCount; ++f1) {
+    const uint32_t features1 = featureList[f1];
+    std::string features1String = "Features: ";
+    features1String += GetFeatureName(featureList[f1]);
+
+    testFeatures(features1, features1String);
+
+    for (uint32_t f2 = f1 + 1u; f2 < featureCount; ++f2) {
+      const uint32_t features12 = f1 | featureList[f2];
+      std::string features12String = features1String + " ";
+      features12String += GetFeatureName(featureList[f2]);
+
+      testFeatures(features12, features12String);
+
+      for (uint32_t f3 = f2 + 1u; f3 < featureCount; ++f3) {
+        const uint32_t features123 = features12 | featureList[f3];
+        std::string features123String = features12String + " ";
+        features123String += GetFeatureName(featureList[f3]);
+
+        testFeatures(features123, features123String);
+      }
+    }
+  }
+}
+
+static void CountCPUDeltas(const Json::Value& aThread, size_t& aOutSamplings,
+                           uint64_t& aOutCPUDeltaSum) {
+  GET_JSON(samples, aThread["samples"], Object);
+  {
+    Json::ArrayIndex threadCPUDeltaIndex = 0;
+    GET_JSON(schema, samples["schema"], Object);
+    {
+      GET_JSON(jsonThreadCPUDeltaIndex, schema["threadCPUDelta"], UInt);
+      threadCPUDeltaIndex = jsonThreadCPUDeltaIndex.asUInt();
+    }
+
+    aOutSamplings = 0;
+    aOutCPUDeltaSum = 0;
+    GET_JSON(data, samples["data"], Array);
+    aOutSamplings = data.size();
+    for (const Json::Value& sample : data) {
+      ASSERT_TRUE(sample.isArray());
+      if (sample.isValidIndex(threadCPUDeltaIndex)) {
+        if (!sample[threadCPUDeltaIndex].isNull()) {
+          GET_JSON(cpuDelta, sample[threadCPUDeltaIndex], UInt64);
+          aOutCPUDeltaSum += uint64_t(cpuDelta.asUInt64());
+        }
+      }
+    }
+  }
+}
+
+TEST(GeckoProfiler, CPUUsage)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  const char* filters[] = {"GeckoMain", "Idle test", "Busy test"};
+
+  enum class TestThreadsState {
+    // Initial state, while constructing and starting the idle thread.
+    STARTING,
+    // Set by the idle thread just before running its main mostly-idle loop.
+    RUNNING1,
+    RUNNING2,
+    // Set by the main thread when it wants the idle thread to stop.
+    STOPPING
+  };
+  Atomic<TestThreadsState> testThreadsState{TestThreadsState::STARTING};
+
+  std::thread idle([&]() {
+    AUTO_PROFILER_REGISTER_THREAD("Idle test");
+    // Add a label to ensure that we have a non-empty stack, even if native
+    // stack-walking is not available.
+    AUTO_PROFILER_LABEL("Idle test", PROFILER);
+    ASSERT_TRUE(testThreadsState.compareExchange(TestThreadsState::STARTING,
+                                                 TestThreadsState::RUNNING1) ||
+                testThreadsState.compareExchange(TestThreadsState::RUNNING1,
+                                                 TestThreadsState::RUNNING2));
+
+    while (testThreadsState != TestThreadsState::STOPPING) {
+      // Sleep for multiple profiler intervals, so the profiler should have
+      // samples with zero CPU utilization.
+      PR_Sleep(PR_MillisecondsToInterval(PROFILER_DEFAULT_INTERVAL * 10));
+    }
+  });
+
+  std::thread busy([&]() {
+    AUTO_PROFILER_REGISTER_THREAD("Busy test");
+    // Add a label to ensure that we have a non-empty stack, even if native
+    // stack-walking is not available.
+    AUTO_PROFILER_LABEL("Busy test", PROFILER);
+    ASSERT_TRUE(testThreadsState.compareExchange(TestThreadsState::STARTING,
+                                                 TestThreadsState::RUNNING1) ||
+                testThreadsState.compareExchange(TestThreadsState::RUNNING1,
+                                                 TestThreadsState::RUNNING2));
+
+    while (testThreadsState != TestThreadsState::STOPPING) {
+      // Stay busy!
+    }
+  });
+
+  // Wait for idle thread to start running its main loop.
+  while (testThreadsState != TestThreadsState::RUNNING2) {
+    PR_Sleep(PR_MillisecondsToInterval(1));
+  }
+
+  // We want to ensure that CPU usage numbers are present whether or not we are
+  // collecting stack samples.
+  static constexpr bool scTestsWithOrWithoutStackSampling[] = {false, true};
+  for (const bool testWithNoStackSampling : scTestsWithOrWithoutStackSampling) {
+    ASSERT_TRUE(!profiler_is_active());
+    ASSERT_TRUE(!profiler_callback_after_sampling(
+        [&](SamplingState) { ASSERT_TRUE(false); }));
+
+    profiler_start(
+        PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+        ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization |
+            (testWithNoStackSampling ? ProfilerFeature::NoStackSampling : 0),
+        filters, MOZ_ARRAY_LENGTH(filters), 0);
+    // Grab a few samples, each with a different label on the stack.
+#  define SAMPLE_LABEL_PREFIX "CPUUsage sample label "
+    static constexpr const char* scSampleLabels[] = {
+        SAMPLE_LABEL_PREFIX "0", SAMPLE_LABEL_PREFIX "1",
+        SAMPLE_LABEL_PREFIX "2", SAMPLE_LABEL_PREFIX "3",
+        SAMPLE_LABEL_PREFIX "4", SAMPLE_LABEL_PREFIX "5",
+        SAMPLE_LABEL_PREFIX "6", SAMPLE_LABEL_PREFIX "7",
+        SAMPLE_LABEL_PREFIX "8", SAMPLE_LABEL_PREFIX "9"};
+    static constexpr size_t scSampleLabelCount =
+        (sizeof(scSampleLabels) / sizeof(scSampleLabels[0]));
+    // We'll do two samplings for each label.
+    static constexpr size_t scMinSamplings = scSampleLabelCount * 2;
+
+    for (const char* sampleLabel : scSampleLabels) {
+      AUTO_PROFILER_LABEL(sampleLabel, OTHER);
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+      // Note: There could have been a delay before this label above, where the
+      // profiler could have sampled the stack and missed the label. By forcing
+      // another sampling now, the label is guaranteed to be present.
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+
+    UniquePtr<char[]> profile = profiler_get_profile();
+
+    if (testWithNoStackSampling) {
+      // If we are testing nostacksampling, we shouldn't find this label prefix
+      // in the profile.
+      EXPECT_FALSE(strstr(profile.get(), SAMPLE_LABEL_PREFIX));
+    } else {
+      // In normal sampling mode, we should find all labels.
+      for (const char* sampleLabel : scSampleLabels) {
+        EXPECT_TRUE(strstr(profile.get(), sampleLabel));
+      }
+    }
+
+    JSONOutputCheck(profile.get(), [testWithNoStackSampling](
+                                       const Json::Value& aRoot) {
+      // Check that the "cpu" feature is present.
+      GET_JSON(meta, aRoot["meta"], Object);
+      {
+        GET_JSON(configuration, meta["configuration"], Object);
+        {
+          GET_JSON(features, configuration["features"], Array);
+          { EXPECT_JSON_ARRAY_CONTAINS(features, String, "cpu"); }
+        }
+      }
+
+      {
+        GET_JSON(sampleUnits, meta["sampleUnits"], Object);
+        {
+          EXPECT_EQ_JSON(sampleUnits["time"], String, "ms");
+          EXPECT_EQ_JSON(sampleUnits["eventDelay"], String, "ms");
+#  if defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+      defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
+          // Note: The exact string is not important here.
+          EXPECT_TRUE(sampleUnits["threadCPUDelta"].isString())
+              << "There should be a sampleUnits.threadCPUDelta on this "
+                 "platform";
+#  else
+        EXPECT_FALSE(sampleUnits.isMember("threadCPUDelta"))
+            << "Unexpected sampleUnits.threadCPUDelta on this platform";;
+#  endif
+        }
+      }
+
+      bool foundMain = false;
+      bool foundIdle = false;
+      uint64_t idleThreadCPUDeltaSum = 0u;
+      bool foundBusy = false;
+      uint64_t busyThreadCPUDeltaSum = 0u;
+
+      // Check that the sample schema contains "threadCPUDelta".
+      GET_JSON(threads, aRoot["threads"], Array);
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          foundMain = true;
+          GET_JSON(samples, thread["samples"], Object);
+          {
+            Json::ArrayIndex stackIndex = 0;
+            Json::ArrayIndex threadCPUDeltaIndex = 0;
+            GET_JSON(schema, samples["schema"], Object);
+            {
+              GET_JSON(jsonStackIndex, schema["stack"], UInt);
+              stackIndex = jsonStackIndex.asUInt();
+              GET_JSON(jsonThreadCPUDeltaIndex, schema["threadCPUDelta"], UInt);
+              threadCPUDeltaIndex = jsonThreadCPUDeltaIndex.asUInt();
+            }
+
+            std::set<uint64_t> stackLeaves;  // To count distinct leaves.
+            unsigned threadCPUDeltaCount = 0;
+            GET_JSON(data, samples["data"], Array);
+            if (testWithNoStackSampling) {
+              // When not sampling stacks, the first sampling loop will have no
+              // running times, so it won't output anything.
+              EXPECT_GE(data.size(), scMinSamplings - 1);
+            } else {
+              EXPECT_GE(data.size(), scMinSamplings);
+            }
+            for (const Json::Value& sample : data) {
+              ASSERT_TRUE(sample.isArray());
+              if (sample.isValidIndex(stackIndex)) {
+                if (!sample[stackIndex].isNull()) {
+                  GET_JSON(stack, sample[stackIndex], UInt64);
+                  stackLeaves.insert(stack.asUInt64());
+                }
+              }
+              if (sample.isValidIndex(threadCPUDeltaIndex)) {
+                if (!sample[threadCPUDeltaIndex].isNull()) {
+                  EXPECT_TRUE(sample[threadCPUDeltaIndex].isUInt64());
+                  ++threadCPUDeltaCount;
+                }
+              }
+            }
+
+            if (testWithNoStackSampling) {
+              // in nostacksampling mode, there should only be one kind of stack
+              // leaf (the root).
+              EXPECT_EQ(stackLeaves.size(), 1u);
+            } else {
+              // in normal sampling mode, there should be at least one kind of
+              // stack leaf for each distinct label.
+              EXPECT_GE(stackLeaves.size(), scSampleLabelCount);
+            }
+
+#  if defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+      defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
+            EXPECT_GE(threadCPUDeltaCount, data.size() - 1u)
+                << "There should be 'threadCPUDelta' values in all but 1 "
+                   "samples";
+#  else
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(threadCPUDeltaCount, 0u);
+#  endif
+          }
+        } else if (name.asString() == "Idle test") {
+          foundIdle = true;
+          size_t samplings;
+          CountCPUDeltas(thread, samplings, idleThreadCPUDeltaSum);
+          if (testWithNoStackSampling) {
+            // When not sampling stacks, the first sampling loop will have no
+            // running times, so it won't output anything.
+            EXPECT_GE(samplings, scMinSamplings - 1);
+          } else {
+            EXPECT_GE(samplings, scMinSamplings);
+          }
+#  if !(defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+        defined(GP_OS_linux) || defined(GP_OS_android) ||  \
+        defined(GP_OS_freebsd))
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(idleThreadCPUDeltaSum, 0u);
+#  endif
+        } else if (name.asString() == "Busy test") {
+          foundBusy = true;
+          size_t samplings;
+          CountCPUDeltas(thread, samplings, busyThreadCPUDeltaSum);
+          if (testWithNoStackSampling) {
+            // When not sampling stacks, the first sampling loop will have no
+            // running times, so it won't output anything.
+            EXPECT_GE(samplings, scMinSamplings - 1);
+          } else {
+            EXPECT_GE(samplings, scMinSamplings);
+          }
+#  if !(defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+        defined(GP_OS_linux) || defined(GP_OS_android) ||  \
+        defined(GP_OS_freebsd))
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(busyThreadCPUDeltaSum, 0u);
+#  endif
+        }
+      }
+
+      EXPECT_TRUE(foundMain);
+      EXPECT_TRUE(foundIdle);
+      EXPECT_TRUE(foundBusy);
+      EXPECT_LE(idleThreadCPUDeltaSum, busyThreadCPUDeltaSum);
+    });
+
+    // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+    // it would require coordination between `profiler_stop()` and another
+    // thread doing `profiler_callback_after_sampling()` at just the right
+    // moment.
+
+    profiler_stop();
+    ASSERT_TRUE(!profiler_is_active());
+    ASSERT_TRUE(!profiler_callback_after_sampling(
+        [&](SamplingState) { ASSERT_TRUE(false); }));
+  }
+
+  testThreadsState = TestThreadsState::STOPPING;
+  busy.join();
+  idle.join();
+}
+
+TEST(GeckoProfiler, AllThreads)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  ASSERT_EQ(static_cast<uint32_t>(ThreadProfilingFeatures::Any), 1u + 2u + 4u)
+      << "This test assumes that there are 3 binary choices 1+2+4; "
+         "Is this test up to date?";
+
+  for (uint32_t threadFeaturesBinary = 0u;
+       threadFeaturesBinary <=
+       static_cast<uint32_t>(ThreadProfilingFeatures::Any);
+       ++threadFeaturesBinary) {
+    ThreadProfilingFeatures threadFeatures =
+        static_cast<ThreadProfilingFeatures>(threadFeaturesBinary);
+    const bool threadCPU = DoFeaturesIntersect(
+        threadFeatures, ThreadProfilingFeatures::CPUUtilization);
+    const bool threadSampling =
+        DoFeaturesIntersect(threadFeatures, ThreadProfilingFeatures::Sampling);
+    const bool threadMarkers =
+        DoFeaturesIntersect(threadFeatures, ThreadProfilingFeatures::Markers);
+
+    ASSERT_TRUE(!profiler_is_active());
+
+    uint32_t features = ProfilerFeature::StackWalk;
+    std::string featuresString = "Features: StackWalk Threads";
+    if (threadCPU) {
+      features |= ProfilerFeature::CPUAllThreads;
+      featuresString += " CPUAllThreads";
+    }
+    if (threadSampling) {
+      features |= ProfilerFeature::SamplingAllThreads;
+      featuresString += " SamplingAllThreads";
+    }
+    if (threadMarkers) {
+      features |= ProfilerFeature::MarkersAllThreads;
+      featuresString += " MarkersAllThreads";
+    }
+
+    SCOPED_TRACE(featuresString.c_str());
+
+    const char* filters[] = {"GeckoMain", "Selected"};
+
+    EXPECT_FALSE(profiler_thread_is_being_profiled(
+        ThreadProfilingFeatures::CPUUtilization));
+    EXPECT_FALSE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+    EXPECT_FALSE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+    EXPECT_FALSE(profiler_thread_is_being_profiled_for_markers());
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    EXPECT_TRUE(profiler_thread_is_being_profiled(
+        ThreadProfilingFeatures::CPUUtilization));
+    EXPECT_TRUE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+    EXPECT_TRUE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+    EXPECT_TRUE(profiler_thread_is_being_profiled_for_markers());
+
+    // This will signal all threads to stop spinning.
+    Atomic<bool> stopThreads{false};
+
+    Atomic<int> selectedThreadSpins{0};
+    std::thread selectedThread([&]() {
+      AUTO_PROFILER_REGISTER_THREAD("Selected test thread");
+      // Add a label to ensure that we have a non-empty stack, even if native
+      // stack-walking is not available.
+      AUTO_PROFILER_LABEL("Selected test thread", PROFILER);
+      EXPECT_TRUE(profiler_thread_is_being_profiled(
+          ThreadProfilingFeatures::CPUUtilization));
+      EXPECT_TRUE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+      EXPECT_TRUE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+      EXPECT_TRUE(profiler_thread_is_being_profiled_for_markers());
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Selected!", PROFILER);
+        ++selectedThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    Atomic<int> unselectedThreadSpins{0};
+    std::thread unselectedThread([&]() {
+      AUTO_PROFILER_REGISTER_THREAD("Registered test thread");
+      // Add a label to ensure that we have a non-empty stack, even if native
+      // stack-walking is not available.
+      AUTO_PROFILER_LABEL("Registered test thread", PROFILER);
+      // This thread is *not* selected for full profiling, but it may still be
+      // profiled depending on the -allthreads features.
+      EXPECT_EQ(profiler_thread_is_being_profiled(
+                    ThreadProfilingFeatures::CPUUtilization),
+                threadCPU);
+      EXPECT_EQ(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling),
+          threadSampling);
+      EXPECT_EQ(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers),
+          threadMarkers);
+      EXPECT_EQ(profiler_thread_is_being_profiled_for_markers(), threadMarkers);
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Registered!", PROFILER);
+        ++unselectedThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    Atomic<int> unregisteredThreadSpins{0};
+    std::thread unregisteredThread([&]() {
+      // No `AUTO_PROFILER_REGISTER_THREAD` here.
+      EXPECT_FALSE(profiler_thread_is_being_profiled(
+          ThreadProfilingFeatures::CPUUtilization));
+      EXPECT_FALSE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+      EXPECT_FALSE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+      EXPECT_FALSE(profiler_thread_is_being_profiled_for_markers());
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Unregistered!", PROFILER);
+        ++unregisteredThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    // Wait for all threads to have started at least one spin.
+    while (selectedThreadSpins == 0 || unselectedThreadSpins == 0 ||
+           unregisteredThreadSpins == 0) {
+      PR_Sleep(PR_MillisecondsToInterval(1));
+    }
+
+    // Wait until the sampler has done at least one loop.
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+    // Restart the spin counts, and ensure each threads will do at least one
+    // more spin each. Since spins are increased after PROFILER_MARKER calls, in
+    // the worst case, each thread will have attempted to record at least one
+    // marker.
+    selectedThreadSpins = 0;
+    unselectedThreadSpins = 0;
+    unregisteredThreadSpins = 0;
+    while (selectedThreadSpins < 1 && unselectedThreadSpins < 1 &&
+           unregisteredThreadSpins < 1) {
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+
+    profiler_pause();
+    UniquePtr<char[]> profile = profiler_get_profile();
+
+    profiler_stop();
+    stopThreads = true;
+    unregisteredThread.join();
+    unselectedThread.join();
+    selectedThread.join();
+
+    JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+      GET_JSON(threads, aRoot["threads"], Array);
+      int foundMain = 0;
+      int foundSelected = 0;
+      int foundSelectedMarker = 0;
+      int foundUnselected = 0;
+      int foundUnselectedMarker = 0;
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(stringTable, thread["stringTable"], Array);
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          ++foundMain;
+          // Don't check the main thread further in this test.
+
+        } else if (name.asString() == "Selected test thread") {
+          ++foundSelected;
+
+          GET_JSON(samples, thread["samples"], Object);
+          GET_JSON(samplesData, samples["data"], Array);
+          EXPECT_GT(samplesData.size(), 0u);
+
+          GET_JSON(markers, thread["markers"], Object);
+          GET_JSON(markersData, markers["data"], Array);
+          for (const Json::Value& marker : markersData) {
+            const unsigned int NAME = 0u;
+            ASSERT_TRUE(marker[NAME].isUInt());  // name id
+            GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+            if (name == "Spinning Selected!") {
+              ++foundSelectedMarker;
+            }
+          }
+        } else if (name.asString() == "Registered test thread") {
+          ++foundUnselected;
+
+          GET_JSON(samples, thread["samples"], Object);
+          GET_JSON(samplesData, samples["data"], Array);
+          if (threadCPU || threadSampling) {
+            EXPECT_GT(samplesData.size(), 0u);
+          } else {
+            EXPECT_EQ(samplesData.size(), 0u);
+          }
+
+          GET_JSON(markers, thread["markers"], Object);
+          GET_JSON(markersData, markers["data"], Array);
+          for (const Json::Value& marker : markersData) {
+            const unsigned int NAME = 0u;
+            ASSERT_TRUE(marker[NAME].isUInt());  // name id
+            GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+            if (name == "Spinning Registered!") {
+              ++foundUnselectedMarker;
+            }
+          }
+
+        } else {
+          EXPECT_STRNE(name.asString().c_str(),
+                       "Unregistered test thread label");
+        }
+      }
+      EXPECT_EQ(foundMain, 1);
+      EXPECT_EQ(foundSelected, 1);
+      EXPECT_GT(foundSelectedMarker, 0);
+      EXPECT_EQ(foundUnselected,
+                (threadCPU || threadSampling || threadMarkers) ? 1 : 0)
+          << "Unselected thread should only be present if at least one of the "
+             "allthreads feature is on";
+      if (threadMarkers) {
+        EXPECT_GT(foundUnselectedMarker, 0);
+      } else {
+        EXPECT_EQ(foundUnselectedMarker, 0);
+      }
+    });
+  }
+}
+
+TEST(GeckoProfiler, FailureHandling)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+  // User-defined marker type that generates a failure when streaming JSON.
+  struct GtestFailingMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-failing");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {
+      aWriter.SetFailure("boom!");
+    }
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+  EXPECT_TRUE(profiler_add_marker("Gtest failing marker",
+                                  geckoprofiler::category::OTHER, {},
+                                  GtestFailingMarker{}));
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  profiler_pause();
+
+  FailureLatchSource failureLatch;
+  SpliceableChunkedJSONWriter w{failureLatch};
+  EXPECT_FALSE(w.Failed());
+  ASSERT_FALSE(w.GetFailure());
+
+  w.Start();
+  EXPECT_FALSE(w.Failed());
+  ASSERT_FALSE(w.GetFailure());
+
+  // The marker will cause a failure during this function call.
+  EXPECT_FALSE(::profiler_stream_json_for_this_process(w));
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  // Already failed, check that we don't crash or reset the failure.
+  EXPECT_FALSE(::profiler_stream_json_for_this_process(w));
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  w.End();
+
+  profiler_stop();
+
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_EQ(profile.get(), nullptr);
+}
+
+#endif  // MOZ_GECKO_PROFILER
diff --git a/tools/profiler/tests/gtest/LulTest.cpp b/tools/profiler/tests/gtest/LulTest.cpp
new file mode 100644
index 0000000000..159a366567
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTest.cpp
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "mozilla/Atomics.h"
+#include "LulMain.h"
+#include "GeckoProfiler.h"       // for TracingKind
+#include "platform-linux-lul.h"  // for read_procmaps
+
+// Set this to 0 to make LUL be completely silent during tests.
+// Set it to 1 to get logging output from LUL, presumably for
+// the purpose of debugging it.
+#define DEBUG_LUL_TEST 0
+
+// LUL needs a callback for its logging sink.
+static void gtest_logging_sink_for_LulIntegration(const char* str) {
+  if (DEBUG_LUL_TEST == 0) {
+    return;
+  }
+  // Ignore any trailing \n, since LOG will add one anyway.
+  size_t n = strlen(str);
+  if (n > 0 && str[n - 1] == '\n') {
+    char* tmp = strdup(str);
+    tmp[n - 1] = 0;
+    fprintf(stderr, "LUL-in-gtest: %s\n", tmp);
+    free(tmp);
+  } else {
+    fprintf(stderr, "LUL-in-gtest: %s\n", str);
+  }
+}
+
+TEST(LulIntegration, unwind_consistency)
+{
+  // Set up LUL and get it to read unwind info for libxul.so, which is
+  // all we care about here, plus (incidentally) practically every
+  // other object in the process too.
+  lul::LUL* lul = new lul::LUL(gtest_logging_sink_for_LulIntegration);
+  read_procmaps(lul);
+
+  // Run unwind tests and receive information about how many there
+  // were and how many were successful.
+  lul->EnableUnwinding();
+  int nTests = 0, nTestsPassed = 0;
+  RunLulUnitTests(&nTests, &nTestsPassed, lul);
+  EXPECT_TRUE(nTests == 6) << "Unexpected number of tests";
+  EXPECT_EQ(nTestsPassed, nTests) << "Not all tests passed";
+
+  delete lul;
+}
diff --git a/tools/profiler/tests/gtest/LulTestDwarf.cpp b/tools/profiler/tests/gtest/LulTestDwarf.cpp
new file mode 100644
index 0000000000..55373ec093
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestDwarf.cpp
@@ -0,0 +1,2733 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include "LulCommonExt.h"
+#include "LulDwarfExt.h"
+#include "LulDwarfInt.h"
+#include "LulTestInfrastructure.h"
+
+using lul_test::CFISection;
+using lul_test::test_assembler::kBigEndian;
+using lul_test::test_assembler::kLittleEndian;
+using lul_test::test_assembler::Label;
+using testing::_;
+using testing::InSequence;
+using testing::Return;
+using testing::Sequence;
+using testing::Test;
+
+#define PERHAPS_WRITE_DEBUG_FRAME_FILE(name, section) /**/
+#define PERHAPS_WRITE_EH_FRAME_FILE(name, section)    /**/
+
+// Set this to 0 to make LUL be completely silent during tests.
+// Set it to 1 to get logging output from LUL, presumably for
+// the purpose of debugging it.
+#define DEBUG_LUL_TEST_DWARF 0
+
+// LUL needs a callback for its logging sink.
+static void gtest_logging_sink_for_LulTestDwarf(const char* str) {
+  if (DEBUG_LUL_TEST_DWARF == 0) {
+    return;
+  }
+  // Ignore any trailing \n, since LOG will add one anyway.
+  size_t n = strlen(str);
+  if (n > 0 && str[n - 1] == '\n') {
+    char* tmp = strdup(str);
+    tmp[n - 1] = 0;
+    fprintf(stderr, "LUL-in-gtest: %s\n", tmp);
+    free(tmp);
+  } else {
+    fprintf(stderr, "LUL-in-gtest: %s\n", str);
+  }
+}
+
+namespace lul {
+
+class MockCallFrameInfoHandler : public CallFrameInfo::Handler {
+ public:
+  MOCK_METHOD6(Entry,
+               bool(size_t offset, uint64 address, uint64 length, uint8 version,
+                    const std::string& augmentation, unsigned return_address));
+  MOCK_METHOD2(UndefinedRule, bool(uint64 address, int reg));
+  MOCK_METHOD2(SameValueRule, bool(uint64 address, int reg));
+  MOCK_METHOD4(OffsetRule,
+               bool(uint64 address, int reg, int base_register, long offset));
+  MOCK_METHOD4(ValOffsetRule,
+               bool(uint64 address, int reg, int base_register, long offset));
+  MOCK_METHOD3(RegisterRule, bool(uint64 address, int reg, int base_register));
+  MOCK_METHOD3(ExpressionRule,
+               bool(uint64 address, int reg, const ImageSlice& expression));
+  MOCK_METHOD3(ValExpressionRule,
+               bool(uint64 address, int reg, const ImageSlice& expression));
+  MOCK_METHOD0(End, bool());
+  MOCK_METHOD2(PersonalityRoutine, bool(uint64 address, bool indirect));
+  MOCK_METHOD2(LanguageSpecificDataArea, bool(uint64 address, bool indirect));
+  MOCK_METHOD0(SignalHandler, bool());
+};
+
+class MockCallFrameErrorReporter : public CallFrameInfo::Reporter {
+ public:
+  MockCallFrameErrorReporter()
+      : Reporter(gtest_logging_sink_for_LulTestDwarf, "mock filename",
+                 "mock section") {}
+  MOCK_METHOD2(Incomplete, void(uint64, CallFrameInfo::EntryKind));
+  MOCK_METHOD1(EarlyEHTerminator, void(uint64));
+  MOCK_METHOD2(CIEPointerOutOfRange, void(uint64, uint64));
+  MOCK_METHOD2(BadCIEId, void(uint64, uint64));
+  MOCK_METHOD2(UnrecognizedVersion, void(uint64, int version));
+  MOCK_METHOD2(UnrecognizedAugmentation, void(uint64, const string&));
+  MOCK_METHOD2(InvalidPointerEncoding, void(uint64, uint8));
+  MOCK_METHOD2(UnusablePointerEncoding, void(uint64, uint8));
+  MOCK_METHOD2(RestoreInCIE, void(uint64, uint64));
+  MOCK_METHOD3(BadInstruction, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(NoCFARule, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(EmptyStateStack, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(ClearingCFARule, void(uint64, CallFrameInfo::EntryKind, uint64));
+};
+
+struct CFIFixture {
+  enum { kCFARegister = CallFrameInfo::Handler::kCFARegister };
+
+  CFIFixture() {
+    // Default expectations for the data handler.
+    //
+    // - Leave Entry and End without expectations, as it's probably a
+    //   good idea to set those explicitly in each test.
+    //
+    // - Expect the *Rule functions to not be called,
+    //   so that each test can simply list the calls they expect.
+    //
+    // I gather I could use StrictMock for this, but the manual seems
+    // to suggest using that only as a last resort, and this isn't so
+    // bad.
+    EXPECT_CALL(handler, UndefinedRule(_, _)).Times(0);
+    EXPECT_CALL(handler, SameValueRule(_, _)).Times(0);
+    EXPECT_CALL(handler, OffsetRule(_, _, _, _)).Times(0);
+    EXPECT_CALL(handler, ValOffsetRule(_, _, _, _)).Times(0);
+    EXPECT_CALL(handler, RegisterRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, ExpressionRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, ValExpressionRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, PersonalityRoutine(_, _)).Times(0);
+    EXPECT_CALL(handler, LanguageSpecificDataArea(_, _)).Times(0);
+    EXPECT_CALL(handler, SignalHandler()).Times(0);
+
+    // Default expectations for the error/warning reporer.
+    EXPECT_CALL(reporter, Incomplete(_, _)).Times(0);
+    EXPECT_CALL(reporter, EarlyEHTerminator(_)).Times(0);
+    EXPECT_CALL(reporter, CIEPointerOutOfRange(_, _)).Times(0);
+    EXPECT_CALL(reporter, BadCIEId(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnrecognizedVersion(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnrecognizedAugmentation(_, _)).Times(0);
+    EXPECT_CALL(reporter, InvalidPointerEncoding(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnusablePointerEncoding(_, _)).Times(0);
+    EXPECT_CALL(reporter, RestoreInCIE(_, _)).Times(0);
+    EXPECT_CALL(reporter, BadInstruction(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, NoCFARule(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, EmptyStateStack(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, ClearingCFARule(_, _, _)).Times(0);
+  }
+
+  MockCallFrameInfoHandler handler;
+  MockCallFrameErrorReporter reporter;
+};
+
+class LulDwarfCFI : public CFIFixture, public Test {};
+
+TEST_F(LulDwarfCFI, EmptyRegion) {
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+  static const char data[1] = {42};
+
+  ByteReader reader(ENDIANNESS_BIG);
+  CallFrameInfo parser(data, 0, &reader, &handler, &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteLength32) {
+  CFISection section(kBigEndian, 8);
+  section
+      // Not even long enough for an initial length.
+      .D16(0xa0f)
+      // Padding to keep valgrind happy. We subtract these off when we
+      // construct the parser.
+      .D16(0);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size() - 2, &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteLength64) {
+  CFISection section(kLittleEndian, 4);
+  section
+      // An incomplete 64-bit DWARF initial length.
+      .D32(0xffffffff)
+      .D32(0x71fbaec2)
+      // Padding to keep valgrind happy. We subtract these off when we
+      // construct the parser.
+      .D32(0);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size() - 4, &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteId32) {
+  CFISection section(kBigEndian, 8);
+  section
+      .D32(3)  // Initial length, not long enough for id
+      .D8(0xd7)
+      .D8(0xe5)
+      .D8(0xf1)  // incomplete id
+      .CIEHeader(8727, 3983, 8889, 3, "")
+      .FinishEntry();
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, BadId32) {
+  CFISection section(kBigEndian, 8);
+  section
+      .D32(0x100)                // Initial length
+      .D32(0xe802fade)           // bogus ID
+      .Append(0x100 - 4, 0x42);  // make the length true
+  section.CIEHeader(1672, 9872, 8529, 3, "").FinishEntry();
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, CIEPointerOutOfRange(_, 0xe802fade)).WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// A lone CIE shouldn't cause any handler calls.
+TEST_F(LulDwarfCFI, SingleCIE) {
+  CFISection section(kLittleEndian, 4);
+  section.CIEHeader(0xffe799a8, 0x3398dcdd, 0x6e9683de, 3, "");
+  section.Append(10, lul::DW_CFA_nop);
+  section.FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("SingleCIE", section);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// One FDE, one CIE.
+TEST_F(LulDwarfCFI, OneFDE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(0x4be22f75, 0x2492236e, 0x6b6efb87, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie, 0x7714740d, 0x3d5a10cd)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("OneFDE", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x7714740d, 0x3d5a10cd, 3, "", 0x6b6efb87))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// Two FDEs share a CIE.
+TEST_F(LulDwarfCFI, TwoFDEsOneCIE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // First FDE. readelf complains about this one because it makes
+      // a forward reference to its CIE.
+      .FDEHeader(cie, 0xa42744df, 0xa3b42121)
+      .FinishEntry()
+      // CIE.
+      .Mark(&cie)
+      .CIEHeader(0x04f7dc7b, 0x3d00c05f, 0xbd43cb59, 3, "")
+      .FinishEntry()
+      // Second FDE.
+      .FDEHeader(cie, 0x6057d391, 0x700f608d)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("TwoFDEsOneCIE", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xa42744df, 0xa3b42121, 3, "", 0xbd43cb59))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x6057d391, 0x700f608d, 3, "", 0xbd43cb59))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// Two FDEs, two CIEs.
+TEST_F(LulDwarfCFI, TwoFDEsTwoCIEs) {
+  CFISection section(kLittleEndian, 8);
+  Label cie1, cie2;
+  section
+      // First CIE.
+      .Mark(&cie1)
+      .CIEHeader(0x694d5d45, 0x4233221b, 0xbf45e65a, 3, "")
+      .FinishEntry()
+      // First FDE which cites second CIE. readelf complains about
+      // this one because it makes a forward reference to its CIE.
+      .FDEHeader(cie2, 0x778b27dfe5871f05ULL, 0x324ace3448070926ULL)
+      .FinishEntry()
+      // Second FDE, which cites first CIE.
+      .FDEHeader(cie1, 0xf6054ca18b10bf5fULL, 0x45fdb970d8bca342ULL)
+      .FinishEntry()
+      // Second CIE.
+      .Mark(&cie2)
+      .CIEHeader(0xfba3fad7, 0x6287e1fd, 0x61d2c581, 2, "")
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("TwoFDEsTwoCIEs", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x778b27dfe5871f05ULL, 0x324ace3448070926ULL,
+                               2, "", 0x61d2c581))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xf6054ca18b10bf5fULL, 0x45fdb970d8bca342ULL,
+                               3, "", 0xbf45e65a))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// An FDE whose CIE specifies a version we don't recognize.
+TEST_F(LulDwarfCFI, BadVersion) {
+  CFISection section(kBigEndian, 4);
+  Label cie1, cie2;
+  section.Mark(&cie1)
+      .CIEHeader(0xca878cf0, 0x7698ec04, 0x7b616f54, 0x52, "")
+      .FinishEntry()
+      // We should skip this entry, as its CIE specifies a version we
+      // don't recognize.
+      .FDEHeader(cie1, 0x08852292, 0x2204004a)
+      .FinishEntry()
+      // Despite the above, we should visit this entry.
+      .Mark(&cie2)
+      .CIEHeader(0x7c3ae7c9, 0xb9b9a512, 0x96cb3264, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie2, 0x2094735a, 0x6e875501)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("BadVersion", section);
+
+  EXPECT_CALL(reporter, UnrecognizedVersion(_, 0x52)).WillOnce(Return());
+
+  {
+    InSequence s;
+    // We should see no mention of the first FDE, but we should get
+    // a call to Entry for the second.
+    EXPECT_CALL(handler, Entry(_, 0x2094735a, 0x6e875501, 3, "", 0x96cb3264))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// An FDE whose CIE specifies an augmentation we don't recognize.
+TEST_F(LulDwarfCFI, BadAugmentation) {
+  CFISection section(kBigEndian, 4);
+  Label cie1, cie2;
+  section.Mark(&cie1)
+      .CIEHeader(0x4be22f75, 0x2492236e, 0x6b6efb87, 3, "spaniels!")
+      .FinishEntry()
+      // We should skip this entry, as its CIE specifies an
+      // augmentation we don't recognize.
+      .FDEHeader(cie1, 0x7714740d, 0x3d5a10cd)
+      .FinishEntry()
+      // Despite the above, we should visit this entry.
+      .Mark(&cie2)
+      .CIEHeader(0xf8bc4399, 0x8cf09931, 0xf2f519b2, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie2, 0x7bf0fda0, 0xcbcd28d8)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("BadAugmentation", section);
+
+  EXPECT_CALL(reporter, UnrecognizedAugmentation(_, "spaniels!"))
+      .WillOnce(Return());
+
+  {
+    InSequence s;
+    // We should see no mention of the first FDE, but we should get
+    // a call to Entry for the second.
+    EXPECT_CALL(handler, Entry(_, 0x7bf0fda0, 0xcbcd28d8, 3, "", 0xf2f519b2))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// The return address column field is a byte in CFI version 1
+// (DWARF2), but a ULEB128 value in version 3 (DWARF3).
+TEST_F(LulDwarfCFI, CIEVersion1ReturnColumn) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, using the version 1 format: return column is a ubyte.
+      .Mark(&cie)
+      // Use a value for the return column that is parsed differently
+      // as a ubyte and as a ULEB128.
+      .CIEHeader(0xbcdea24f, 0x5be28286, 0x9f, 1, "")
+      .FinishEntry()
+      // FDE, citing that CIE.
+      .FDEHeader(cie, 0xb8d347b5, 0x825e55dc)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("CIEVersion1ReturnColumn", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xb8d347b5, 0x825e55dc, 1, "", 0x9f))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// The return address column field is a byte in CFI version 1
+// (DWARF2), but a ULEB128 value in version 3 (DWARF3).
+TEST_F(LulDwarfCFI, CIEVersion3ReturnColumn) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, using the version 3 format: return column is a ULEB128.
+      .Mark(&cie)
+      // Use a value for the return column that is parsed differently
+      // as a ubyte and as a ULEB128.
+      .CIEHeader(0x0ab4758d, 0xc010fdf7, 0x89, 3, "")
+      .FinishEntry()
+      // FDE, citing that CIE.
+      .FDEHeader(cie, 0x86763f2b, 0x2a66dc23)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("CIEVersion3ReturnColumn", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x86763f2b, 0x2a66dc23, 3, "", 0x89))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+struct CFIInsnFixture : public CFIFixture {
+  CFIInsnFixture() : CFIFixture() {
+    data_factor = 0xb6f;
+    return_register = 0x9be1ed9f;
+    version = 3;
+    cfa_base_register = 0x383a3aa;
+    cfa_offset = 0xf748;
+  }
+
+  // Prepare SECTION to receive FDE instructions.
+  //
+  // - Append a stock CIE header that establishes the fixture's
+  //   code_factor, data_factor, return_register, version, and
+  //   augmentation values.
+  // - Have the CIE set up a CFA rule using cfa_base_register and
+  //   cfa_offset.
+  // - Append a stock FDE header, referring to the above CIE, for the
+  //   fde_size bytes at fde_start. Choose fde_start and fde_size
+  //   appropriately for the section's address size.
+  // - Set appropriate expectations on handler in sequence s for the
+  //   frame description entry and the CIE's CFA rule.
+  //
+  // On return, SECTION is ready to have FDE instructions appended to
+  // it, and its FinishEntry member called.
+  void StockCIEAndFDE(CFISection* section) {
+    // Choose appropriate constants for our address size.
+    if (section->AddressSize() == 4) {
+      fde_start = 0xc628ecfbU;
+      fde_size = 0x5dee04a2;
+      code_factor = 0x60b;
+    } else {
+      assert(section->AddressSize() == 8);
+      fde_start = 0x0005c57ce7806bd3ULL;
+      fde_size = 0x2699521b5e333100ULL;
+      code_factor = 0x01008e32855274a8ULL;
+    }
+
+    // Create the CIE.
+    (*section)
+        .Mark(&cie_label)
+        .CIEHeader(code_factor, data_factor, return_register, version, "")
+        .D8(lul::DW_CFA_def_cfa)
+        .ULEB128(cfa_base_register)
+        .ULEB128(cfa_offset)
+        .FinishEntry();
+
+    // Create the FDE.
+    section->FDEHeader(cie_label, fde_start, fde_size);
+
+    // Expect an Entry call for the FDE and a ValOffsetRule call for the
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .InSequence(s)
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister,
+                                       cfa_base_register, cfa_offset))
+        .InSequence(s)
+        .WillOnce(Return(true));
+  }
+
+  // Run the contents of SECTION through a CallFrameInfo parser,
+  // expecting parser.Start to return SUCCEEDS.  Caller may optionally
+  // supply, via READER, its own ByteReader.  If that's absent, a
+  // local one is used.
+  void ParseSection(CFISection* section, bool succeeds = true,
+                    ByteReader* reader = nullptr) {
+    string contents;
+    EXPECT_TRUE(section->GetContents(&contents));
+    lul::Endianness endianness;
+    if (section->endianness() == kBigEndian)
+      endianness = ENDIANNESS_BIG;
+    else {
+      assert(section->endianness() == kLittleEndian);
+      endianness = ENDIANNESS_LITTLE;
+    }
+    ByteReader local_reader(endianness);
+    ByteReader* reader_to_use = reader ? reader : &local_reader;
+    reader_to_use->SetAddressSize(section->AddressSize());
+    CallFrameInfo parser(contents.data(), contents.size(), reader_to_use,
+                         &handler, &reporter);
+    if (succeeds)
+      EXPECT_TRUE(parser.Start());
+    else
+      EXPECT_FALSE(parser.Start());
+  }
+
+  Label cie_label;
+  Sequence s;
+  uint64 code_factor;
+  int data_factor;
+  unsigned return_register;
+  unsigned version;
+  unsigned cfa_base_register;
+  int cfa_offset;
+  uint64 fde_start, fde_size;
+};
+
+class LulDwarfCFIInsn : public CFIInsnFixture, public Test {};
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_set_loc) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_set_loc)
+      .D32(0xb1ee3e7a)
+      // Use DW_CFA_def_cfa to force a handler call that we can use to
+      // check the effect of the DW_CFA_set_loc.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x4defb431)
+      .ULEB128(0x6d17b0ee)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_set_loc", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(0xb1ee3e7a, kCFARegister, 0x4defb431, 0x6d17b0ee))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section
+      .D8(lul::DW_CFA_advance_loc | 0x2a)
+      // Use DW_CFA_def_cfa to force a handler call that we can use to
+      // check the effect of the DW_CFA_advance_loc.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x5bbb3715)
+      .ULEB128(0x0186c7bf)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc", section);
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 0x2a * code_factor,
+                                     kCFARegister, 0x5bbb3715, 0x0186c7bf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc1) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc1)
+      .D8(0xd8)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x69d5696a)
+      .ULEB128(0x1eb7fc93)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc1", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0xd8 * code_factor),
+                                     kCFARegister, 0x69d5696a, 0x1eb7fc93))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc2) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc2)
+      .D16(0x3adb)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x3a368bed)
+      .ULEB128(0x3194ee37)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc2", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0x3adb * code_factor),
+                                     kCFARegister, 0x3a368bed, 0x3194ee37))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc4) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc4)
+      .D32(0x15813c88)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x135270c5)
+      .ULEB128(0x24bad7cb)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc4", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0x15813c88ULL * code_factor),
+                                     kCFARegister, 0x135270c5, 0x24bad7cb))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_MIPS_advance_loc8) {
+  code_factor = 0x2d;
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_MIPS_advance_loc8)
+      .D64(0x3c4f3945b92c14ULL)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0xe17ed602)
+      .ULEB128(0x3d162e7f)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc8", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule((fde_start + 0x3c4f3945b92c14ULL * code_factor),
+                            kCFARegister, 0xe17ed602, 0x3d162e7f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x4e363a85)
+      .ULEB128(0x815f9aa7)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_def_cfa", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x4e363a85, 0x815f9aa7))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_sf) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_sf)
+      .ULEB128(0x8ccb32b7)
+      .LEB128(0x9ea)
+      .D8(lul::DW_CFA_def_cfa_sf)
+      .ULEB128(0x9b40f5da)
+      .LEB128(-0x40a2)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, 0x8ccb32b7,
+                                     0x9ea * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, 0x9b40f5da,
+                                     -0x40a2 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_register) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_register).ULEB128(0x3e7e9363).FinishEntry();
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x3e7e9363, cfa_offset))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// DW_CFA_def_cfa_register should have no effect when applied to a
+// non-base/offset rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_registerBadRule) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  ImageSlice expr("needle in a haystack");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_expression)
+      .Block(expr)
+      .D8(lul::DW_CFA_def_cfa_register)
+      .ULEB128(0xf1b49e49)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .WillRepeatedly(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_offset).ULEB128(0x1e8e3b9b).FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     0x1e8e3b9b))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offset_sf) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_offset_sf)
+      .LEB128(0x970)
+      .D8(lul::DW_CFA_def_cfa_offset_sf)
+      .LEB128(-0x2cd)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     0x970 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     -0x2cd * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// DW_CFA_def_cfa_offset should have no effect when applied to a
+// non-base/offset rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offsetBadRule) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  ImageSlice expr("six ways to Sunday");
+  section.D8(lul::DW_CFA_def_cfa_expression)
+      .Block(expr)
+      .D8(lul::DW_CFA_def_cfa_offset)
+      .ULEB128(0x1e8e3b9b)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .WillRepeatedly(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_expression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 8);
+  ImageSlice expr("eating crow");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_expression).Block(expr).FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_undefined) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined).ULEB128(0x300ce45d).FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x300ce45d))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_same_value) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value).ULEB128(0x3865a760).FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0x3865a760))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x2c).ULEB128(0x9f6).FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x2c, kCFARegister, 0x9f6 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset_extended) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x402b)
+      .ULEB128(0xb48)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x402b, kCFARegister, 0xb48 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset_extended_sf) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset_extended_sf)
+      .ULEB128(0x997c23ee)
+      .LEB128(0x2d00)
+      .D8(lul::DW_CFA_offset_extended_sf)
+      .ULEB128(0x9519eb82)
+      .LEB128(-0xa77)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x997c23ee, kCFARegister,
+                                  0x2d00 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x9519eb82, kCFARegister,
+                                  -0xa77 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x623562fe)
+      .ULEB128(0x673)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x623562fe, kCFARegister,
+                                     0x673 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_offset_sf) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset_sf)
+      .ULEB128(0x6f4f)
+      .LEB128(0xaab)
+      .D8(lul::DW_CFA_val_offset_sf)
+      .ULEB128(0x2483)
+      .LEB128(-0x8a2)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x6f4f, kCFARegister,
+                                     0xaab * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x2483, kCFARegister,
+                                     -0x8a2 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_register) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0x278d18f9)
+      .ULEB128(0x1a684414)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0x278d18f9, 0x1a684414))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_expression) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  ImageSlice expr("plus ça change, plus c'est la même chose");
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0xa1619fb2)
+      .Block(expr)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0xa1619fb2, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_expression) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  ImageSlice expr("he who has the gold makes the rules");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0xc5e4a9e3)
+      .Block(expr)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0xc5e4a9e3, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restore) {
+  CFISection section(kLittleEndian, 8);
+  code_factor = 0x01bd188a9b1fa083ULL;
+  data_factor = -0x1ac8;
+  return_register = 0x8c35b049;
+  version = 2;
+  fde_start = 0x2d70fe998298bbb1ULL;
+  fde_size = 0x46ccc2e63cf0b108ULL;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "")
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x6ca1d50e)
+      .ULEB128(0x372e38e8)
+      // Provide an offset(N) rule for register 0x3c.
+      .D8(lul::DW_CFA_offset | 0x3c)
+      .ULEB128(0xb348)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide a new offset(N) rule for register 0x3c.
+      .D8(lul::DW_CFA_advance_loc | 0x13)
+      .D8(lul::DW_CFA_offset | 0x3c)
+      .ULEB128(0x9a50)
+      // At a third address, restore the original rule for register 0x3c.
+      .D8(lul::DW_CFA_advance_loc | 0x01)
+      .D8(lul::DW_CFA_restore | 0x3c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x6ca1d50e, 0x372e38e8))
+        .WillOnce(Return(true));
+    // CIE's rule for register 0x3c.
+    EXPECT_CALL(handler,
+                OffsetRule(fde_start, 0x3c, kCFARegister, 0xb348 * data_factor))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x3c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x13 * code_factor, 0x3c,
+                                    kCFARegister, 0x9a50 * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's rule for register 0x3c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + (0x13 + 0x01) * code_factor,
+                                    0x3c, kCFARegister, 0xb348 * data_factor))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restoreNoRule) {
+  CFISection section(kBigEndian, 4);
+  code_factor = 0x005f78143c1c3b82ULL;
+  data_factor = 0x25d0;
+  return_register = 0xe8;
+  version = 1;
+  fde_start = 0x4062e30f;
+  fde_size = 0x5302a389;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "")
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x470aa334)
+      .ULEB128(0x099ef127)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide an offset(N) rule for register 0x2c.
+      .D8(lul::DW_CFA_advance_loc | 0x7)
+      .D8(lul::DW_CFA_offset | 0x2c)
+      .ULEB128(0x1f47)
+      // At a third address, restore the (missing) CIE rule for register 0x2c.
+      .D8(lul::DW_CFA_advance_loc | 0xb)
+      .D8(lul::DW_CFA_restore | 0x2c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x470aa334, 0x099ef127))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x2c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x7 * code_factor, 0x2c,
+                                    kCFARegister, 0x1f47 * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's (missing) rule for register 0x2c.
+    EXPECT_CALL(handler,
+                SameValueRule(fde_start + (0x7 + 0xb) * code_factor, 0x2c))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restore_extended) {
+  CFISection section(kBigEndian, 4);
+  code_factor = 0x126e;
+  data_factor = -0xd8b;
+  return_register = 0x77711787;
+  version = 3;
+  fde_start = 0x01f55a45;
+  fde_size = 0x452adb80;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "",
+                 true /* dwarf64 */)
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x56fa0edd)
+      .ULEB128(0x097f78a5)
+      // Provide an offset(N) rule for register 0x0f9b8a1c.
+      .D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x0f9b8a1c)
+      .ULEB128(0xc979)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide a new offset(N) rule for reg 0x0f9b8a1c.
+      .D8(lul::DW_CFA_advance_loc | 0x3)
+      .D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x0f9b8a1c)
+      .ULEB128(0x3b7b)
+      // At a third address, restore the original rule for register 0x0f9b8a1c.
+      .D8(lul::DW_CFA_advance_loc | 0x04)
+      .D8(lul::DW_CFA_restore_extended)
+      .ULEB128(0x0f9b8a1c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x56fa0edd, 0x097f78a5))
+        .WillOnce(Return(true));
+    // CIE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler, OffsetRule(fde_start, 0x0f9b8a1c, kCFARegister,
+                                    0xc979 * data_factor))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x3 * code_factor, 0x0f9b8a1c,
+                                    kCFARegister, 0x3b7b * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler,
+                OffsetRule(fde_start + (0x3 + 0x4) * code_factor, 0x0f9b8a1c,
+                           kCFARegister, 0xc979 * data_factor))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_remember_and_restore_state) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+
+  // We create a state, save it, modify it, and then restore. We
+  // refer to the state that is overridden the restore as the
+  // "outgoing" state, and the restored state the "incoming" state.
+  //
+  // Register         outgoing        incoming        expect
+  // 1                offset(N)       no rule         new "same value" rule
+  // 2                register(R)     offset(N)       report changed rule
+  // 3                offset(N)       offset(M)       report changed offset
+  // 4                offset(N)       offset(N)       no report
+  // 5                offset(N)       no rule         new "same value" rule
+  section
+      // Create the "incoming" state, which we will save and later restore.
+      .D8(lul::DW_CFA_offset | 2)
+      .ULEB128(0x9806)
+      .D8(lul::DW_CFA_offset | 3)
+      .ULEB128(0x995d)
+      .D8(lul::DW_CFA_offset | 4)
+      .ULEB128(0x7055)
+      .D8(lul::DW_CFA_remember_state)
+      // Advance to a new instruction; an implementation could legitimately
+      // ignore all but the final rule for a given register at a given address.
+      .D8(lul::DW_CFA_advance_loc | 1)
+      // Create the "outgoing" state, which we will discard.
+      .D8(lul::DW_CFA_offset | 1)
+      .ULEB128(0xea1a)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(2)
+      .ULEB128(0x1d2a3767)
+      .D8(lul::DW_CFA_offset | 3)
+      .ULEB128(0xdd29)
+      .D8(lul::DW_CFA_offset | 5)
+      .ULEB128(0xf1ce)
+      // At a third address, restore the incoming state.
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  uint64 addr = fde_start;
+
+  // Expect the incoming rules to be reported.
+  EXPECT_CALL(handler, OffsetRule(addr, 2, kCFARegister, 0x9806 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0x995d * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 4, kCFARegister, 0x7055 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  addr += code_factor;
+
+  // After the save, we establish the outgoing rule set.
+  EXPECT_CALL(handler, OffsetRule(addr, 1, kCFARegister, 0xea1a * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, RegisterRule(addr, 2, 0x1d2a3767))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0xdd29 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 5, kCFARegister, 0xf1ce * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  addr += code_factor;
+
+  // Finally, after the restore, expect to see the differences from
+  // the outgoing to the incoming rules reported.
+  EXPECT_CALL(handler, SameValueRule(addr, 1))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 2, kCFARegister, 0x9806 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0x995d * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(addr, 5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// Check that restoring a rule set reports changes to the CFA rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_remember_and_restore_stateCFA) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+
+  section.D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_def_cfa_offset)
+      .ULEB128(0x90481102)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor, kCFARegister,
+                                     cfa_base_register, 0x90481102))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor * 2, kCFARegister,
+                                     cfa_base_register, cfa_offset))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_nop) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_nop)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x3fb8d4f1)
+      .ULEB128(0x078dc67b)
+      .D8(lul::DW_CFA_nop)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x3fb8d4f1, 0x078dc67b))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_window_save) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_window_save).FinishEntry();
+
+  // Don't include all the rules in any particular sequence.
+
+  // The caller's %o0-%o7 have become the callee's %i0-%i7. This is
+  // the GCC register numbering.
+  for (int i = 8; i < 16; i++)
+    EXPECT_CALL(handler, RegisterRule(fde_start, i, i + 16))
+        .WillOnce(Return(true));
+  // The caller's %l0-%l7 and %i0-%i7 have been saved at the top of
+  // its frame.
+  for (int i = 16; i < 32; i++)
+    EXPECT_CALL(handler, OffsetRule(fde_start, i, kCFARegister, (i - 16) * 4))
+        .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_args_size) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_args_size)
+      .ULEB128(0xeddfa520)
+      // Verify that we see this, meaning we parsed the above properly.
+      .D8(lul::DW_CFA_offset | 0x23)
+      .ULEB128(0x269)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x23, kCFARegister, 0x269 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_negative_offset_extended) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_negative_offset_extended)
+      .ULEB128(0x430cc87a)
+      .ULEB128(0x613)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x430cc87a, kCFARegister,
+                                  -0x613 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// Three FDEs: skip the second
+TEST_F(LulDwarfCFIInsn, SkipFDE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, used by all FDEs.
+      .Mark(&cie)
+      .CIEHeader(0x010269f2, 0x9177, 0xedca5849, 2, "")
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x42ed390b)
+      .ULEB128(0x98f43aad)
+      .FinishEntry()
+      // First FDE.
+      .FDEHeader(cie, 0xa870ebdd, 0x60f6aa4)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x3a860351)
+      .ULEB128(0x6c9a6bcf)
+      .FinishEntry()
+      // Second FDE.
+      .FDEHeader(cie, 0xc534f7c0, 0xf6552e9, true /* dwarf64 */)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x1b62c234)
+      .ULEB128(0x26586b18)
+      .FinishEntry()
+      // Third FDE.
+      .FDEHeader(cie, 0xf681cfc8, 0x7e4594e)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x26c53934)
+      .ULEB128(0x18eeb8a4)
+      .FinishEntry();
+
+  {
+    InSequence s;
+
+    // Process the first FDE.
+    EXPECT_CALL(handler, Entry(_, 0xa870ebdd, 0x60f6aa4, 2, "", 0xedca5849))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler,
+                ValOffsetRule(0xa870ebdd, kCFARegister, 0x42ed390b, 0x98f43aad))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, RegisterRule(0xa870ebdd, 0x3a860351, 0x6c9a6bcf))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+    // Skip the second FDE.
+    EXPECT_CALL(handler, Entry(_, 0xc534f7c0, 0xf6552e9, 2, "", 0xedca5849))
+        .WillOnce(Return(false));
+
+    // Process the third FDE.
+    EXPECT_CALL(handler, Entry(_, 0xf681cfc8, 0x7e4594e, 2, "", 0xedca5849))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler,
+                ValOffsetRule(0xf681cfc8, kCFARegister, 0x42ed390b, 0x98f43aad))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, RegisterRule(0xf681cfc8, 0x26c53934, 0x18eeb8a4))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+// Quit processing in the middle of an entry's instructions.
+TEST_F(LulDwarfCFIInsn, QuitMidentry) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xe0cf850d)
+      .ULEB128(0x15aab431)
+      .D8(lul::DW_CFA_expression)
+      .ULEB128(0x46750aa5)
+      .Block("meat")
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xe0cf850d, 0x15aab431))
+      .InSequence(s)
+      .WillOnce(Return(false));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, false);
+}
+
+class LulDwarfCFIRestore : public CFIInsnFixture, public Test {};
+
+TEST_F(LulDwarfCFIRestore, RestoreUndefinedRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined)
+      .ULEB128(0x0bac878e)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x0bac878e))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreUndefinedRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined)
+      .ULEB128(0x7dedff5f)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_same_value)
+      .ULEB128(0x7dedff5f)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(fde_start + code_factor, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + 2 * code_factor, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreSameValueRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value)
+      .ULEB128(0xadbc9b3a)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0xadbc9b3a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreSameValueRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value)
+      .ULEB128(0x3d90dcb5)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x3d90dcb5)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(fde_start + 2 * code_factor, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x14)
+      .ULEB128(0xb6f)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x14, kCFARegister, 0xb6f * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0xeb7)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x21)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x21, kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0x21))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + 2 * code_factor, 0x21,
+                                  kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleChangedOffset) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0x134)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0xf4f)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x21, kCFARegister, 0x134 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + code_factor, 0x21, kCFARegister,
+                                  0xf4f * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + 2 * code_factor, 0x21,
+                                  kCFARegister, 0x134 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x829caee6)
+      .ULEB128(0xe4c)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x829caee6, kCFARegister,
+                                     0xe4c * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0xf17c36d6)
+      .ULEB128(0xeb7)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xf17c36d6)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0xf17c36d6, kCFARegister,
+                                     0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xf17c36d6))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 2 * code_factor, 0xf17c36d6,
+                                     kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleChangedValOffset) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x2cf0ab1b)
+      .ULEB128(0x562)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x2cf0ab1b)
+      .ULEB128(0xe88)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x2cf0ab1b, kCFARegister,
+                                     0x562 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor, 0x2cf0ab1b,
+                                     kCFARegister, 0xe88 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 2 * code_factor, 0x2cf0ab1b,
+                                     kCFARegister, 0x562 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0x77514acc)
+      .ULEB128(0x464de4ce)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0x77514acc, 0x464de4ce))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xe39acce5)
+      .ULEB128(0x095f1559)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xe39acce5)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xe39acce5, 0x095f1559))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xe39acce5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + 2 * code_factor, 0xe39acce5, 0x095f1559))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleChangedRegister) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xd40e21b1)
+      .ULEB128(0x16607d6a)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0xd40e21b1)
+      .ULEB128(0xbabb4742)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xd40e21b1, 0x16607d6a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + code_factor, 0xd40e21b1, 0xbabb4742))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + 2 * code_factor, 0xd40e21b1, 0x16607d6a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleUnchanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice dwarf("dwarf");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0x666ae152)
+      .Block("dwarf")
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0x666ae152, dwarf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleChanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice elf("elf");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0xb5ca5c46)
+      .Block(elf)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xb5ca5c46)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0xb5ca5c46, elf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xb5ca5c46))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              ExpressionRule(fde_start + 2 * code_factor, 0xb5ca5c46, elf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleChangedExpression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  ImageSlice smurf("smurf");
+  ImageSlice orc("orc");
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0x500f5739)
+      .Block(smurf)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_expression)
+      .ULEB128(0x500f5739)
+      .Block(orc)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0x500f5739, smurf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ExpressionRule(fde_start + code_factor, 0x500f5739, orc))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  // Expectations are not wishes.
+  EXPECT_CALL(handler,
+              ExpressionRule(fde_start + 2 * code_factor, 0x500f5739, smurf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleUnchanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice hideous("hideous");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x666ae152)
+      .Block(hideous)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0x666ae152, hideous))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleChanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice revolting("revolting");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0xb5ca5c46)
+      .Block(revolting)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xb5ca5c46)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("RestoreValExpressionRuleChanged", section);
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0xb5ca5c46, revolting))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xb5ca5c46))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValExpressionRule(fde_start + 2 * code_factor,
+                                         0xb5ca5c46, revolting))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleChangedValExpression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice repulsive("repulsive");
+  ImageSlice nauseous("nauseous");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x500f5739)
+      .Block(repulsive)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x500f5739)
+      .Block(nauseous)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("RestoreValExpressionRuleChangedValExpression",
+                                 section);
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0x500f5739, repulsive))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              ValExpressionRule(fde_start + code_factor, 0x500f5739, nauseous))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  // Expectations are not wishes.
+  EXPECT_CALL(handler, ValExpressionRule(fde_start + 2 * code_factor,
+                                         0x500f5739, repulsive))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+struct EHFrameFixture : public CFIInsnFixture {
+  EHFrameFixture() : CFIInsnFixture(), section(kBigEndian, 4, true) {
+    encoded_pointer_bases.cfi = 0x7f496cb2;
+    encoded_pointer_bases.text = 0x540f67b6;
+    encoded_pointer_bases.data = 0xe3eab768;
+    section.SetEncodedPointerBases(encoded_pointer_bases);
+  }
+  CFISection section;
+  CFISection::EncodedPointerBases encoded_pointer_bases;
+
+  // Parse CFIInsnFixture::ParseSection, but parse the section as
+  // .eh_frame data, supplying stock base addresses.
+  void ParseEHFrameSection(CFISection* section, bool succeeds = true) {
+    EXPECT_TRUE(section->ContainsEHFrame());
+    string contents;
+    EXPECT_TRUE(section->GetContents(&contents));
+    lul::Endianness endianness;
+    if (section->endianness() == kBigEndian)
+      endianness = ENDIANNESS_BIG;
+    else {
+      assert(section->endianness() == kLittleEndian);
+      endianness = ENDIANNESS_LITTLE;
+    }
+    ByteReader reader(endianness);
+    reader.SetAddressSize(section->AddressSize());
+    reader.SetCFIDataBase(encoded_pointer_bases.cfi, contents.data());
+    reader.SetTextBase(encoded_pointer_bases.text);
+    reader.SetDataBase(encoded_pointer_bases.data);
+    CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                         &reporter, true);
+    if (succeeds)
+      EXPECT_TRUE(parser.Start());
+    else
+      EXPECT_FALSE(parser.Start());
+  }
+};
+
+class LulDwarfEHFrame : public EHFrameFixture, public Test {};
+
+// A simple CIE, an FDE, and a terminator.
+TEST_F(LulDwarfEHFrame, Terminator) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(9968, 2466, 67, 1, "")
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(3772)
+      .ULEB128(1372)
+      .FinishEntry()
+      .FDEHeader(cie, 0x848037a1, 0x7b30475e)
+      .D8(lul::DW_CFA_set_loc)
+      .D32(0x17713850)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(5721)
+      .FinishEntry()
+      .D32(0)  // Terminate the sequence.
+      // This FDE should be ignored.
+      .FDEHeader(cie, 0xf19629fe, 0x439fb09b)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.Terminator", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x848037a1, 0x7b30475e, 1, "", 67))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0x848037a1, kCFARegister, 3772, 1372))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0x17713850, 5721))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(reporter, EarlyEHTerminator(_)).InSequence(s).WillOnce(Return());
+
+  ParseEHFrameSection(&section);
+}
+
+// The parser should recognize the Linux Standards Base 'z' augmentations.
+TEST_F(LulDwarfEHFrame, SimpleFDE) {
+  lul::DwarfPointerEncoding lsda_encoding = lul::DwarfPointerEncoding(
+      lul::DW_EH_PE_indirect | lul::DW_EH_PE_datarel | lul::DW_EH_PE_sdata2);
+  lul::DwarfPointerEncoding fde_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_textrel | lul::DW_EH_PE_udata2);
+
+  section.SetPointerEncoding(fde_encoding);
+  section.SetEncodedPointerBases(encoded_pointer_bases);
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(4873, 7012, 100, 1, "zSLPR")
+      .ULEB128(7)               // Augmentation data length
+      .D8(lsda_encoding)        // LSDA pointer format
+      .D8(lul::DW_EH_PE_pcrel)  // personality pointer format
+      .EncodedPointer(0x97baa00, lul::DW_EH_PE_pcrel)  // and value
+      .D8(fde_encoding)                                // FDE pointer format
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(6706)
+      .ULEB128(31)
+      .FinishEntry()
+      .FDEHeader(cie, 0x540f6b56, 0xf686)
+      .ULEB128(2)                                 // Augmentation data length
+      .EncodedPointer(0xe3eab475, lsda_encoding)  // LSDA pointer, signed
+      .D8(lul::DW_CFA_set_loc)
+      .EncodedPointer(0x540fa4ce, fde_encoding)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x675e)
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.SimpleFDE", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x540f6b56, 0xf686, 1, "zSLPR", 100))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, PersonalityRoutine(0x97baa00, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, LanguageSpecificDataArea(0xe3eab475, true))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SignalHandler()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0x540f6b56, kCFARegister, 6706, 31))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0x540fa4ce, 0x675e))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// Check that we can handle an empty 'z' augmentation.
+TEST_F(LulDwarfEHFrame, EmptyZ) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(5955, 5805, 228, 1, "z")
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(3629)
+      .ULEB128(247)
+      .FinishEntry()
+      .FDEHeader(cie, 0xda007738, 0xfb55c641)
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_advance_loc1)
+      .D8(11)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(3769)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.EmptyZ", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xda007738, 0xfb55c641, 1, "z", 228))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0xda007738, kCFARegister, 3629, 247))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0xda007738 + 11 * 5955, 3769))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// Check that we recognize bad 'z' augmentation characters.
+TEST_F(LulDwarfEHFrame, BadZ) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(6937, 1045, 142, 1, "zQ")
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(9006)
+      .ULEB128(7725)
+      .FinishEntry()
+      .FDEHeader(cie, 0x1293efa8, 0x236f53f2)
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_advance_loc | 12)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(5667)
+      .ULEB128(3462)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.BadZ", section);
+
+  EXPECT_CALL(reporter, UnrecognizedAugmentation(_, "zQ")).WillOnce(Return());
+
+  ParseEHFrameSection(&section, false);
+}
+
+TEST_F(LulDwarfEHFrame, zL) {
+  Label cie;
+  lul::DwarfPointerEncoding lsda_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_funcrel | lul::DW_EH_PE_udata2);
+  section.Mark(&cie)
+      .CIEHeader(9285, 9959, 54, 1, "zL")
+      .ULEB128(1)         // Augmentation data length
+      .D8(lsda_encoding)  // encoding for LSDA pointer in FDE
+
+      .FinishEntry()
+      .FDEHeader(cie, 0xd40091aa, 0x9aa6e746)
+      .ULEB128(2)                                 // Augmentation data length
+      .EncodedPointer(0xd40099cd, lsda_encoding)  // LSDA pointer
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zL", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xd40091aa, 0x9aa6e746, 1, "zL", 54))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, LanguageSpecificDataArea(0xd40099cd, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zP) {
+  Label cie;
+  lul::DwarfPointerEncoding personality_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_datarel | lul::DW_EH_PE_udata2);
+  section.Mark(&cie)
+      .CIEHeader(1097, 6313, 17, 1, "zP")
+      .ULEB128(3)                // Augmentation data length
+      .D8(personality_encoding)  // encoding for personality routine
+      .EncodedPointer(0xe3eaccac, personality_encoding)  // value
+      .FinishEntry()
+      .FDEHeader(cie, 0x0c8350c9, 0xbef11087)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zP", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x0c8350c9, 0xbef11087, 1, "zP", 17))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, PersonalityRoutine(0xe3eaccac, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zR) {
+  Label cie;
+  lul::DwarfPointerEncoding pointer_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_textrel | lul::DW_EH_PE_sdata2);
+  section.SetPointerEncoding(pointer_encoding);
+  section.Mark(&cie)
+      .CIEHeader(8011, 5496, 75, 1, "zR")
+      .ULEB128(1)            // Augmentation data length
+      .D8(pointer_encoding)  // encoding for FDE addresses
+      .FinishEntry()
+      .FDEHeader(cie, 0x540f9431, 0xbd0)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zR", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x540f9431, 0xbd0, 1, "zR", 75))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zS) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(9217, 7694, 57, 1, "zS")
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .FDEHeader(cie, 0xd40091aa, 0x9aa6e746)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zS", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xd40091aa, 0x9aa6e746, 1, "zS", 57))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SignalHandler()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// These tests require manual inspection of the test output.
+struct CFIReporterFixture {
+  CFIReporterFixture()
+      : reporter(gtest_logging_sink_for_LulTestDwarf, "test file name",
+                 "test section name") {}
+  CallFrameInfo::Reporter reporter;
+};
+
+class LulDwarfCFIReporter : public CFIReporterFixture, public Test {};
+
+TEST_F(LulDwarfCFIReporter, Incomplete) {
+  reporter.Incomplete(0x0102030405060708ULL, CallFrameInfo::kUnknown);
+}
+
+TEST_F(LulDwarfCFIReporter, EarlyEHTerminator) {
+  reporter.EarlyEHTerminator(0x0102030405060708ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, CIEPointerOutOfRange) {
+  reporter.CIEPointerOutOfRange(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, BadCIEId) {
+  reporter.BadCIEId(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, UnrecognizedVersion) {
+  reporter.UnrecognizedVersion(0x0123456789abcdefULL, 43);
+}
+
+TEST_F(LulDwarfCFIReporter, UnrecognizedAugmentation) {
+  reporter.UnrecognizedAugmentation(0x0123456789abcdefULL, "poodles");
+}
+
+TEST_F(LulDwarfCFIReporter, InvalidPointerEncoding) {
+  reporter.InvalidPointerEncoding(0x0123456789abcdefULL, 0x42);
+}
+
+TEST_F(LulDwarfCFIReporter, UnusablePointerEncoding) {
+  reporter.UnusablePointerEncoding(0x0123456789abcdefULL, 0x42);
+}
+
+TEST_F(LulDwarfCFIReporter, RestoreInCIE) {
+  reporter.RestoreInCIE(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, BadInstruction) {
+  reporter.BadInstruction(0x0123456789abcdefULL, CallFrameInfo::kFDE,
+                          0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, NoCFARule) {
+  reporter.NoCFARule(0x0123456789abcdefULL, CallFrameInfo::kCIE,
+                     0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, EmptyStateStack) {
+  reporter.EmptyStateStack(0x0123456789abcdefULL, CallFrameInfo::kTerminator,
+                           0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, ClearingCFARule) {
+  reporter.ClearingCFARule(0x0123456789abcdefULL, CallFrameInfo::kFDE,
+                           0xfedcba9876543210ULL);
+}
+class LulDwarfExpr : public Test {};
+
+class MockSummariser : public Summariser {
+ public:
+  MockSummariser() : Summariser(nullptr, 0, nullptr) {}
+  MOCK_METHOD2(Entry, void(uintptr_t, uintptr_t));
+  MOCK_METHOD0(End, void());
+  MOCK_METHOD5(Rule, void(uintptr_t, int, LExprHow, int16_t, int64_t));
+  MOCK_METHOD1(AddPfxInstr, uint32_t(PfxInstr));
+};
+
+TEST_F(LulDwarfExpr, SimpleTransliteration) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_lit0)
+      .D8(DW_OP_lit31)
+      .D8(DW_OP_breg0 + 17)
+      .LEB128(-1234)
+      .D8(DW_OP_const4s)
+      .D32(0xFEDC9876)
+      .D8(DW_OP_deref)
+      .D8(DW_OP_and)
+      .D8(DW_OP_plus)
+      .D8(DW_OP_minus)
+      .D8(DW_OP_shl)
+      .D8(DW_OP_ge);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+    // DW_OP_lit0
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 0)));
+    // DW_OP_lit31
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 31)));
+    // DW_OP_breg17 -1234
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_DwReg, 17)));
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, -1234)));
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Add)));
+    // DW_OP_const4s 0xFEDC9876
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 0xFEDC9876)));
+    // DW_OP_deref
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Deref)));
+    // DW_OP_and
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_And)));
+    // DW_OP_plus
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Add)));
+    // DW_OP_minus
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Sub)));
+    // DW_OP_shl
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Shl)));
+    // DW_OP_ge
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_CmpGES)));
+    // required end marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_End)));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix >= 0);
+}
+
+TEST_F(LulDwarfExpr, UnknownOpcode) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_lo_user - 1);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix == -1);
+}
+
+TEST_F(LulDwarfExpr, ExpressionOverrun) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_const4s).D8(0x12).D8(0x34).D8(0x56);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+    // DW_OP_const4s followed by 3 (a.k.a. not enough) bytes
+    // We expect PfxInstr(PX_Simm32, not-known-for-sure-32-bit-immediate)
+    // Hence must use _ as the argument.
+    EXPECT_CALL(summ, AddPfxInstr(_));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix == -1);
+}
+
+// We'll need to mention specific Dwarf registers in the EvaluatePfxExpr tests,
+// and those names are arch-specific, so a bit of macro magic is helpful.
+#if defined(GP_ARCH_arm)
+#  define TESTED_REG_STRUCT_NAME r11
+#  define TESTED_REG_DWARF_NAME DW_REG_ARM_R11
+#elif defined(GP_ARCH_arm64)
+#  define TESTED_REG_STRUCT_NAME x29
+#  define TESTED_REG_DWARF_NAME DW_REG_AARCH64_X29
+#elif defined(GP_ARCH_amd64) || defined(GP_ARCH_x86)
+#  define TESTED_REG_STRUCT_NAME xbp
+#  define TESTED_REG_DWARF_NAME DW_REG_INTEL_XBP
+#else
+#  error "Unknown plat"
+#endif
+
+struct EvaluatePfxExprFixture {
+  // Creates:
+  // initial stack, AVMA 0x12345678, at offset 4 bytes = 0xdeadbeef
+  // initial regs, with XBP = 0x14141356
+  // initial CFA = 0x5432ABCD
+  EvaluatePfxExprFixture() {
+    // The test stack.
+    si.mStartAvma = 0x12345678;
+    si.mLen = 0;
+#define XX(_byte)                      \
+  do {                                 \
+    si.mContents[si.mLen++] = (_byte); \
+  } while (0)
+    XX(0x55);
+    XX(0x55);
+    XX(0x55);
+    XX(0x55);
+    if (sizeof(void*) == 8) {
+      // le64
+      XX(0xEF);
+      XX(0xBE);
+      XX(0xAD);
+      XX(0xDE);
+      XX(0);
+      XX(0);
+      XX(0);
+      XX(0);
+    } else {
+      // le32
+      XX(0xEF);
+      XX(0xBE);
+      XX(0xAD);
+      XX(0xDE);
+    }
+    XX(0xAA);
+    XX(0xAA);
+    XX(0xAA);
+    XX(0xAA);
+#undef XX
+    // The initial CFA.
+    initialCFA = TaggedUWord(0x5432ABCD);
+    // The initial register state.
+    memset(&regs, 0, sizeof(regs));
+    regs.TESTED_REG_STRUCT_NAME = TaggedUWord(0x14141356);
+  }
+
+  StackImage si;
+  TaggedUWord initialCFA;
+  UnwindRegs regs;
+};
+
+class LulDwarfEvaluatePfxExpr : public EvaluatePfxExprFixture, public Test {};
+
+TEST_F(LulDwarfEvaluatePfxExpr, NormalEvaluation) {
+  vector<PfxInstr> instrs;
+  // Put some junk at the start of the insn sequence.
+  instrs.push_back(PfxInstr(PX_End));
+  instrs.push_back(PfxInstr(PX_End));
+
+  // Now the real sequence
+  // stack is empty
+  instrs.push_back(PfxInstr(PX_Start, 1));
+  // 0x5432ABCD
+  instrs.push_back(PfxInstr(PX_SImm32, 0x31415927));
+  // 0x5432ABCD 0x31415927
+  instrs.push_back(PfxInstr(PX_DwReg, TESTED_REG_DWARF_NAME));
+  // 0x5432ABCD 0x31415927 0x14141356
+  instrs.push_back(PfxInstr(PX_SImm32, 42));
+  // 0x5432ABCD 0x31415927 0x14141356 42
+  instrs.push_back(PfxInstr(PX_Sub));
+  // 0x5432ABCD 0x31415927 0x1414132c
+  instrs.push_back(PfxInstr(PX_Add));
+  // 0x5432ABCD 0x45556c53
+  instrs.push_back(PfxInstr(PX_SImm32, si.mStartAvma + 4));
+  // 0x5432ABCD 0x45556c53 0x1234567c
+  instrs.push_back(PfxInstr(PX_Deref));
+  // 0x5432ABCD 0x45556c53 0xdeadbeef
+  instrs.push_back(PfxInstr(PX_SImm32, 0xFE01DC23));
+  // 0x5432ABCD 0x45556c53 0xdeadbeef 0xFE01DC23
+  instrs.push_back(PfxInstr(PX_And));
+  // 0x5432ABCD 0x45556c53 0xde019c23
+  instrs.push_back(PfxInstr(PX_SImm32, 7));
+  // 0x5432ABCD 0x45556c53 0xde019c23 7
+  instrs.push_back(PfxInstr(PX_Shl));
+  // 0x5432ABCD 0x45556c53 0x6f00ce1180
+  instrs.push_back(PfxInstr(PX_SImm32, 0x7fffffff));
+  // 0x5432ABCD 0x45556c53 0x6f00ce1180 7fffffff
+  instrs.push_back(PfxInstr(PX_And));
+  // 0x5432ABCD 0x45556c53 0x00ce1180
+  instrs.push_back(PfxInstr(PX_Add));
+  // 0x5432ABCD 0x46237dd3
+  instrs.push_back(PfxInstr(PX_Sub));
+  // 0xe0f2dfa
+
+  instrs.push_back(PfxInstr(PX_End));
+
+  TaggedUWord res = EvaluatePfxExpr(2 /*offset of start insn*/, &regs,
+                                    initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res.Value() == 0xe0f2dfa);
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, EmptySequence) {
+  vector<PfxInstr> instrs;
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, BogusStartPoint) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_SImm32, 42));
+  instrs.push_back(PfxInstr(PX_SImm32, 24));
+  instrs.push_back(PfxInstr(PX_SImm32, 4224));
+  TaggedUWord res = EvaluatePfxExpr(1, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, MissingEndMarker) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_SImm32, 24));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackUnderflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackNoUnderflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 1 /*push the initial CFA*/));
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == initialCFA);
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackOverflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  for (int i = 0; i < 10 + 1; i++) {
+    instrs.push_back(PfxInstr(PX_SImm32, i + 100));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackNoOverflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  for (int i = 0; i < 10 + 0; i++) {
+    instrs.push_back(PfxInstr(PX_SImm32, i + 100));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == TaggedUWord(109));
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, OutOfRangeShl) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_SImm32, 1234));
+  instrs.push_back(PfxInstr(PX_SImm32, 5678));
+  instrs.push_back(PfxInstr(PX_Shl));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(!res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, TestCmpGES) {
+  const int32_t argsL[6] = {0, 0, 1, -2, -1, -2};
+  const int32_t argsR[6] = {0, 1, 0, -2, -2, -1};
+  // expecting:              t  f  t  t   t    f   = 101110 = 0x2E
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  // The "running total"
+  instrs.push_back(PfxInstr(PX_SImm32, 0));
+  for (unsigned int i = 0; i < sizeof(argsL) / sizeof(argsL[0]); i++) {
+    // Shift the "running total" at the bottom of the stack left by one bit
+    instrs.push_back(PfxInstr(PX_SImm32, 1));
+    instrs.push_back(PfxInstr(PX_Shl));
+    // Push both test args and do the comparison
+    instrs.push_back(PfxInstr(PX_SImm32, argsL[i]));
+    instrs.push_back(PfxInstr(PX_SImm32, argsR[i]));
+    instrs.push_back(PfxInstr(PX_CmpGES));
+    // Or the result into the running total
+    instrs.push_back(PfxInstr(PX_Or));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == TaggedUWord(0x2E));
+}
+
+}  // namespace lul
diff --git a/tools/profiler/tests/gtest/LulTestInfrastructure.cpp b/tools/profiler/tests/gtest/LulTestInfrastructure.cpp
new file mode 100644
index 0000000000..6d49557e9c
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestInfrastructure.cpp
@@ -0,0 +1,498 @@
+// Copyright (c) 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Derived from:
+// test_assembler.cc: Implementation of google_breakpad::TestAssembler.
+// See test_assembler.h for details.
+
+// Derived from:
+// cfi_assembler.cc: Implementation of google_breakpad::CFISection class.
+// See cfi_assembler.h for details.
+
+#include "LulTestInfrastructure.h"
+
+#include "LulDwarfInt.h"
+
+#include <cassert>
+
+namespace lul_test {
+namespace test_assembler {
+
+using std::back_insert_iterator;
+
+Label::Label() : value_(new Binding()) {}
+Label::Label(uint64_t value) : value_(new Binding(value)) {}
+Label::Label(const Label& label) {
+  value_ = label.value_;
+  value_->Acquire();
+}
+Label::~Label() {
+  if (value_->Release()) delete value_;
+}
+
+Label& Label::operator=(uint64_t value) {
+  value_->Set(NULL, value);
+  return *this;
+}
+
+Label& Label::operator=(const Label& label) {
+  value_->Set(label.value_, 0);
+  return *this;
+}
+
+Label Label::operator+(uint64_t addend) const {
+  Label l;
+  l.value_->Set(this->value_, addend);
+  return l;
+}
+
+Label Label::operator-(uint64_t subtrahend) const {
+  Label l;
+  l.value_->Set(this->value_, -subtrahend);
+  return l;
+}
+
+// When NDEBUG is #defined, assert doesn't evaluate its argument. This
+// means you can't simply use assert to check the return value of a
+// function with necessary side effects.
+//
+// ALWAYS_EVALUATE_AND_ASSERT(x) evaluates x regardless of whether
+// NDEBUG is #defined; when NDEBUG is not #defined, it further asserts
+// that x is true.
+#ifdef NDEBUG
+#  define ALWAYS_EVALUATE_AND_ASSERT(x) x
+#else
+#  define ALWAYS_EVALUATE_AND_ASSERT(x) assert(x)
+#endif
+
+uint64_t Label::operator-(const Label& label) const {
+  uint64_t offset;
+  ALWAYS_EVALUATE_AND_ASSERT(IsKnownOffsetFrom(label, &offset));
+  return offset;
+}
+
+bool Label::IsKnownConstant(uint64_t* value_p) const {
+  Binding* base;
+  uint64_t addend;
+  value_->Get(&base, &addend);
+  if (base != NULL) return false;
+  if (value_p) *value_p = addend;
+  return true;
+}
+
+bool Label::IsKnownOffsetFrom(const Label& label, uint64_t* offset_p) const {
+  Binding *label_base, *this_base;
+  uint64_t label_addend, this_addend;
+  label.value_->Get(&label_base, &label_addend);
+  value_->Get(&this_base, &this_addend);
+  // If this and label are related, Get will find their final
+  // common ancestor, regardless of how indirect the relation is. This
+  // comparison also handles the constant vs. constant case.
+  if (this_base != label_base) return false;
+  if (offset_p) *offset_p = this_addend - label_addend;
+  return true;
+}
+
+Label::Binding::Binding() : base_(this), addend_(), reference_count_(1) {}
+
+Label::Binding::Binding(uint64_t addend)
+    : base_(NULL), addend_(addend), reference_count_(1) {}
+
+Label::Binding::~Binding() {
+  assert(reference_count_ == 0);
+  if (base_ && base_ != this && base_->Release()) delete base_;
+}
+
+void Label::Binding::Set(Binding* binding, uint64_t addend) {
+  if (!base_ && !binding) {
+    // We're equating two constants. This could be okay.
+    assert(addend_ == addend);
+  } else if (!base_) {
+    // We are a known constant, but BINDING may not be, so turn the
+    // tables and try to set BINDING's value instead.
+    binding->Set(NULL, addend_ - addend);
+  } else {
+    if (binding) {
+      // Find binding's final value. Since the final value is always either
+      // completely unconstrained or a constant, never a reference to
+      // another variable (otherwise, it wouldn't be final), this
+      // guarantees we won't create cycles here, even for code like this:
+      //   l = m, m = n, n = l;
+      uint64_t binding_addend;
+      binding->Get(&binding, &binding_addend);
+      addend += binding_addend;
+    }
+
+    // It seems likely that setting a binding to itself is a bug
+    // (although I can imagine this might turn out to be helpful to
+    // permit).
+    assert(binding != this);
+
+    if (base_ != this) {
+      // Set the other bindings on our chain as well. Note that this
+      // is sufficient even though binding relationships form trees:
+      // All binding operations traverse their chains to the end, and
+      // all bindings related to us share some tail of our chain, so
+      // they will see the changes we make here.
+      base_->Set(binding, addend - addend_);
+      // We're not going to use base_ any more.
+      if (base_->Release()) delete base_;
+    }
+
+    // Adopt BINDING as our base. Note that it should be correct to
+    // acquire here, after the release above, even though the usual
+    // reference-counting rules call for acquiring first, and then
+    // releasing: the self-reference assertion above should have
+    // complained if BINDING were 'this' or anywhere along our chain,
+    // so we didn't release BINDING.
+    if (binding) binding->Acquire();
+    base_ = binding;
+    addend_ = addend;
+  }
+}
+
+void Label::Binding::Get(Binding** base, uint64_t* addend) {
+  if (base_ && base_ != this) {
+    // Recurse to find the end of our reference chain (the root of our
+    // tree), and then rewrite every binding along the chain to refer
+    // to it directly, adjusting addends appropriately. (This is why
+    // this member function isn't this-const.)
+    Binding* final_base;
+    uint64_t final_addend;
+    base_->Get(&final_base, &final_addend);
+    if (final_base) final_base->Acquire();
+    if (base_->Release()) delete base_;
+    base_ = final_base;
+    addend_ += final_addend;
+  }
+  *base = base_;
+  *addend = addend_;
+}
+
+template <typename Inserter>
+static inline void InsertEndian(test_assembler::Endianness endianness,
+                                size_t size, uint64_t number, Inserter dest) {
+  assert(size > 0);
+  if (endianness == kLittleEndian) {
+    for (size_t i = 0; i < size; i++) {
+      *dest++ = (char)(number & 0xff);
+      number >>= 8;
+    }
+  } else {
+    assert(endianness == kBigEndian);
+    // The loop condition is odd, but it's correct for size_t.
+    for (size_t i = size - 1; i < size; i--)
+      *dest++ = (char)((number >> (i * 8)) & 0xff);
+  }
+}
+
+Section& Section::Append(Endianness endianness, size_t size, uint64_t number) {
+  InsertEndian(endianness, size, number,
+               back_insert_iterator<string>(contents_));
+  return *this;
+}
+
+Section& Section::Append(Endianness endianness, size_t size,
+                         const Label& label) {
+  // If this label's value is known, there's no reason to waste an
+  // entry in references_ on it.
+  uint64_t value;
+  if (label.IsKnownConstant(&value)) return Append(endianness, size, value);
+
+  // This will get caught when the references are resolved, but it's
+  // nicer to find out earlier.
+  assert(endianness != kUnsetEndian);
+
+  references_.push_back(Reference(contents_.size(), endianness, size, label));
+  contents_.append(size, 0);
+  return *this;
+}
+
+#define ENDIANNESS_L kLittleEndian
+#define ENDIANNESS_B kBigEndian
+#define ENDIANNESS(e) ENDIANNESS_##e
+
+#define DEFINE_SHORT_APPEND_NUMBER_ENDIAN(e, bits)         \
+  Section& Section::e##bits(uint##bits##_t v) {            \
+    InsertEndian(ENDIANNESS(e), bits / 8, v,               \
+                 back_insert_iterator<string>(contents_)); \
+    return *this;                                          \
+  }
+
+#define DEFINE_SHORT_APPEND_LABEL_ENDIAN(e, bits) \
+  Section& Section::e##bits(const Label& v) {     \
+    return Append(ENDIANNESS(e), bits / 8, v);    \
+  }
+
+// Define L16, B32, and friends.
+#define DEFINE_SHORT_APPEND_ENDIAN(e, bits)  \
+  DEFINE_SHORT_APPEND_NUMBER_ENDIAN(e, bits) \
+  DEFINE_SHORT_APPEND_LABEL_ENDIAN(e, bits)
+
+DEFINE_SHORT_APPEND_LABEL_ENDIAN(L, 8);
+DEFINE_SHORT_APPEND_LABEL_ENDIAN(B, 8);
+DEFINE_SHORT_APPEND_ENDIAN(L, 16);
+DEFINE_SHORT_APPEND_ENDIAN(L, 32);
+DEFINE_SHORT_APPEND_ENDIAN(L, 64);
+DEFINE_SHORT_APPEND_ENDIAN(B, 16);
+DEFINE_SHORT_APPEND_ENDIAN(B, 32);
+DEFINE_SHORT_APPEND_ENDIAN(B, 64);
+
+#define DEFINE_SHORT_APPEND_NUMBER_DEFAULT(bits)           \
+  Section& Section::D##bits(uint##bits##_t v) {            \
+    InsertEndian(endianness_, bits / 8, v,                 \
+                 back_insert_iterator<string>(contents_)); \
+    return *this;                                          \
+  }
+#define DEFINE_SHORT_APPEND_LABEL_DEFAULT(bits) \
+  Section& Section::D##bits(const Label& v) {   \
+    return Append(endianness_, bits / 8, v);    \
+  }
+#define DEFINE_SHORT_APPEND_DEFAULT(bits)  \
+  DEFINE_SHORT_APPEND_NUMBER_DEFAULT(bits) \
+  DEFINE_SHORT_APPEND_LABEL_DEFAULT(bits)
+
+DEFINE_SHORT_APPEND_LABEL_DEFAULT(8)
+DEFINE_SHORT_APPEND_DEFAULT(16);
+DEFINE_SHORT_APPEND_DEFAULT(32);
+DEFINE_SHORT_APPEND_DEFAULT(64);
+
+Section& Section::LEB128(long long value) {
+  while (value < -0x40 || 0x3f < value) {
+    contents_ += (value & 0x7f) | 0x80;
+    if (value < 0)
+      value = (value >> 7) | ~(((unsigned long long)-1) >> 7);
+    else
+      value = (value >> 7);
+  }
+  contents_ += value & 0x7f;
+  return *this;
+}
+
+Section& Section::ULEB128(uint64_t value) {
+  while (value > 0x7f) {
+    contents_ += (value & 0x7f) | 0x80;
+    value = (value >> 7);
+  }
+  contents_ += value;
+  return *this;
+}
+
+Section& Section::Align(size_t alignment, uint8_t pad_byte) {
+  // ALIGNMENT must be a power of two.
+  assert(((alignment - 1) & alignment) == 0);
+  size_t new_size = (contents_.size() + alignment - 1) & ~(alignment - 1);
+  contents_.append(new_size - contents_.size(), pad_byte);
+  assert((contents_.size() & (alignment - 1)) == 0);
+  return *this;
+}
+
+bool Section::GetContents(string* contents) {
+  // For each label reference, find the label's value, and patch it into
+  // the section's contents.
+  for (size_t i = 0; i < references_.size(); i++) {
+    Reference& r = references_[i];
+    uint64_t value;
+    if (!r.label.IsKnownConstant(&value)) {
+      fprintf(stderr, "Undefined label #%zu at offset 0x%zx\n", i, r.offset);
+      return false;
+    }
+    assert(r.offset < contents_.size());
+    assert(contents_.size() - r.offset >= r.size);
+    InsertEndian(r.endianness, r.size, value, contents_.begin() + r.offset);
+  }
+  contents->clear();
+  std::swap(contents_, *contents);
+  references_.clear();
+  return true;
+}
+
+}  // namespace test_assembler
+}  // namespace lul_test
+
+namespace lul_test {
+
+CFISection& CFISection::CIEHeader(uint64_t code_alignment_factor,
+                                  int data_alignment_factor,
+                                  unsigned return_address_register,
+                                  uint8_t version, const string& augmentation,
+                                  bool dwarf64) {
+  assert(!entry_length_);
+  entry_length_ = new PendingLength();
+  in_fde_ = false;
+
+  if (dwarf64) {
+    D32(kDwarf64InitialLengthMarker);
+    D64(entry_length_->length);
+    entry_length_->start = Here();
+    D64(eh_frame_ ? kEHFrame64CIEIdentifier : kDwarf64CIEIdentifier);
+  } else {
+    D32(entry_length_->length);
+    entry_length_->start = Here();
+    D32(eh_frame_ ? kEHFrame32CIEIdentifier : kDwarf32CIEIdentifier);
+  }
+  D8(version);
+  AppendCString(augmentation);
+  ULEB128(code_alignment_factor);
+  LEB128(data_alignment_factor);
+  if (version == 1)
+    D8(return_address_register);
+  else
+    ULEB128(return_address_register);
+  return *this;
+}
+
+CFISection& CFISection::FDEHeader(Label cie_pointer, uint64_t initial_location,
+                                  uint64_t address_range, bool dwarf64) {
+  assert(!entry_length_);
+  entry_length_ = new PendingLength();
+  in_fde_ = true;
+  fde_start_address_ = initial_location;
+
+  if (dwarf64) {
+    D32(0xffffffff);
+    D64(entry_length_->length);
+    entry_length_->start = Here();
+    if (eh_frame_)
+      D64(Here() - cie_pointer);
+    else
+      D64(cie_pointer);
+  } else {
+    D32(entry_length_->length);
+    entry_length_->start = Here();
+    if (eh_frame_)
+      D32(Here() - cie_pointer);
+    else
+      D32(cie_pointer);
+  }
+  EncodedPointer(initial_location);
+  // The FDE length in an .eh_frame section uses the same encoding as the
+  // initial location, but ignores the base address (selected by the upper
+  // nybble of the encoding), as it's a length, not an address that can be
+  // made relative.
+  EncodedPointer(address_range, DwarfPointerEncoding(pointer_encoding_ & 0x0f));
+  return *this;
+}
+
+CFISection& CFISection::FinishEntry() {
+  assert(entry_length_);
+  Align(address_size_, lul::DW_CFA_nop);
+  entry_length_->length = Here() - entry_length_->start;
+  delete entry_length_;
+  entry_length_ = NULL;
+  in_fde_ = false;
+  return *this;
+}
+
+CFISection& CFISection::EncodedPointer(uint64_t address,
+                                       DwarfPointerEncoding encoding,
+                                       const EncodedPointerBases& bases) {
+  // Omitted data is extremely easy to emit.
+  if (encoding == lul::DW_EH_PE_omit) return *this;
+
+  // If (encoding & lul::DW_EH_PE_indirect) != 0, then we assume
+  // that ADDRESS is the address at which the pointer is stored --- in
+  // other words, that bit has no effect on how we write the pointer.
+  encoding = DwarfPointerEncoding(encoding & ~lul::DW_EH_PE_indirect);
+
+  // Find the base address to which this pointer is relative. The upper
+  // nybble of the encoding specifies this.
+  uint64_t base;
+  switch (encoding & 0xf0) {
+    case lul::DW_EH_PE_absptr:
+      base = 0;
+      break;
+    case lul::DW_EH_PE_pcrel:
+      base = bases.cfi + Size();
+      break;
+    case lul::DW_EH_PE_textrel:
+      base = bases.text;
+      break;
+    case lul::DW_EH_PE_datarel:
+      base = bases.data;
+      break;
+    case lul::DW_EH_PE_funcrel:
+      base = fde_start_address_;
+      break;
+    case lul::DW_EH_PE_aligned:
+      base = 0;
+      break;
+    default:
+      abort();
+  };
+
+  // Make ADDRESS relative. Yes, this is appropriate even for "absptr"
+  // values; see gcc/unwind-pe.h.
+  address -= base;
+
+  // Align the pointer, if required.
+  if ((encoding & 0xf0) == lul::DW_EH_PE_aligned) Align(AddressSize());
+
+  // Append ADDRESS to this section in the appropriate form. For the
+  // fixed-width forms, we don't need to differentiate between signed and
+  // unsigned encodings, because ADDRESS has already been extended to 64
+  // bits before it was passed to us.
+  switch (encoding & 0x0f) {
+    case lul::DW_EH_PE_absptr:
+      Address(address);
+      break;
+
+    case lul::DW_EH_PE_uleb128:
+      ULEB128(address);
+      break;
+
+    case lul::DW_EH_PE_sleb128:
+      LEB128(address);
+      break;
+
+    case lul::DW_EH_PE_udata2:
+    case lul::DW_EH_PE_sdata2:
+      D16(address);
+      break;
+
+    case lul::DW_EH_PE_udata4:
+    case lul::DW_EH_PE_sdata4:
+      D32(address);
+      break;
+
+    case lul::DW_EH_PE_udata8:
+    case lul::DW_EH_PE_sdata8:
+      D64(address);
+      break;
+
+    default:
+      abort();
+  }
+
+  return *this;
+};
+
+}  // namespace lul_test
diff --git a/tools/profiler/tests/gtest/LulTestInfrastructure.h b/tools/profiler/tests/gtest/LulTestInfrastructure.h
new file mode 100644
index 0000000000..a48353071f
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestInfrastructure.h
@@ -0,0 +1,735 @@
+// -*- mode: C++ -*-
+
+// Copyright (c) 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Derived from:
+// cfi_assembler.h: Define CFISection, a class for creating properly
+// (and improperly) formatted DWARF CFI data for unit tests.
+
+// Derived from:
+// test-assembler.h: interface to class for building complex binary streams.
+
+// To test the Breakpad symbol dumper and processor thoroughly, for
+// all combinations of host system and minidump processor
+// architecture, we need to be able to easily generate complex test
+// data like debugging information and minidump files.
+//
+// For example, if we want our unit tests to provide full code
+// coverage for stack walking, it may be difficult to persuade the
+// compiler to generate every possible sort of stack walking
+// information that we want to support; there are probably DWARF CFI
+// opcodes that GCC never emits. Similarly, if we want to test our
+// error handling, we will need to generate damaged minidumps or
+// debugging information that (we hope) the client or compiler will
+// never produce on its own.
+//
+// google_breakpad::TestAssembler provides a predictable and
+// (relatively) simple way to generate complex formatted data streams
+// like minidumps and CFI. Furthermore, because TestAssembler is
+// portable, developers without access to (say) Visual Studio or a
+// SPARC assembler can still work on test data for those targets.
+
+#ifndef LUL_TEST_INFRASTRUCTURE_H
+#define LUL_TEST_INFRASTRUCTURE_H
+
+#include "LulDwarfExt.h"
+
+#include <string>
+#include <vector>
+
+using std::string;
+using std::vector;
+
+namespace lul_test {
+namespace test_assembler {
+
+// A Label represents a value not yet known that we need to store in a
+// section. As long as all the labels a section refers to are defined
+// by the time we retrieve its contents as bytes, we can use undefined
+// labels freely in that section's construction.
+//
+// A label can be in one of three states:
+// - undefined,
+// - defined as the sum of some other label and a constant, or
+// - a constant.
+//
+// A label's value never changes, but it can accumulate constraints.
+// Adding labels and integers is permitted, and yields a label.
+// Subtracting a constant from a label is permitted, and also yields a
+// label. Subtracting two labels that have some relationship to each
+// other is permitted, and yields a constant.
+//
+// For example:
+//
+//   Label a;               // a's value is undefined
+//   Label b;               // b's value is undefined
+//   {
+//     Label c = a + 4;     // okay, even though a's value is unknown
+//     b = c + 4;           // also okay; b is now a+8
+//   }
+//   Label d = b - 2;       // okay; d == a+6, even though c is gone
+//   d.Value();             // error: d's value is not yet known
+//   d - a;                 // is 6, even though their values are not known
+//   a = 12;                // now b == 20, and d == 18
+//   d.Value();             // 18: no longer an error
+//   b.Value();             // 20
+//   d = 10;                // error: d is already defined.
+//
+// Label objects' lifetimes are unconstrained: notice that, in the
+// above example, even though a and b are only related through c, and
+// c goes out of scope, the assignment to a sets b's value as well. In
+// particular, it's not necessary to ensure that a Label lives beyond
+// Sections that refer to it.
+class Label {
+ public:
+  Label();                         // An undefined label.
+  explicit Label(uint64_t value);  // A label with a fixed value
+  Label(const Label& value);       // A label equal to another.
+  ~Label();
+
+  Label& operator=(uint64_t value);
+  Label& operator=(const Label& value);
+  Label operator+(uint64_t addend) const;
+  Label operator-(uint64_t subtrahend) const;
+  uint64_t operator-(const Label& subtrahend) const;
+
+  // We could also provide == and != that work on undefined, but
+  // related, labels.
+
+  // Return true if this label's value is known. If VALUE_P is given,
+  // set *VALUE_P to the known value if returning true.
+  bool IsKnownConstant(uint64_t* value_p = NULL) const;
+
+  // Return true if the offset from LABEL to this label is known. If
+  // OFFSET_P is given, set *OFFSET_P to the offset when returning true.
+  //
+  // You can think of l.KnownOffsetFrom(m, &d) as being like 'd = l-m',
+  // except that it also returns a value indicating whether the
+  // subtraction is possible given what we currently know of l and m.
+  // It can be possible even if we don't know l and m's values. For
+  // example:
+  //
+  //   Label l, m;
+  //   m = l + 10;
+  //   l.IsKnownConstant();             // false
+  //   m.IsKnownConstant();             // false
+  //   uint64_t d;
+  //   l.IsKnownOffsetFrom(m, &d);      // true, and sets d to -10.
+  //   l-m                              // -10
+  //   m-l                              // 10
+  //   m.Value()                        // error: m's value is not known
+  bool IsKnownOffsetFrom(const Label& label, uint64_t* offset_p = NULL) const;
+
+ private:
+  // A label's value, or if that is not yet known, how the value is
+  // related to other labels' values. A binding may be:
+  // - a known constant,
+  // - constrained to be equal to some other binding plus a constant, or
+  // - unconstrained, and free to take on any value.
+  //
+  // Many labels may point to a single binding, and each binding may
+  // refer to another, so bindings and labels form trees whose leaves
+  // are labels, whose interior nodes (and roots) are bindings, and
+  // where links point from children to parents. Bindings are
+  // reference counted, allowing labels to be lightweight, copyable,
+  // assignable, placed in containers, and so on.
+  class Binding {
+   public:
+    Binding();
+    explicit Binding(uint64_t addend);
+    ~Binding();
+
+    // Increment our reference count.
+    void Acquire() { reference_count_++; };
+    // Decrement our reference count, and return true if it is zero.
+    bool Release() { return --reference_count_ == 0; }
+
+    // Set this binding to be equal to BINDING + ADDEND. If BINDING is
+    // NULL, then set this binding to the known constant ADDEND.
+    // Update every binding on this binding's chain to point directly
+    // to BINDING, or to be a constant, with addends adjusted
+    // appropriately.
+    void Set(Binding* binding, uint64_t value);
+
+    // Return what we know about the value of this binding.
+    // - If this binding's value is a known constant, set BASE to
+    //   NULL, and set ADDEND to its value.
+    // - If this binding is not a known constant but related to other
+    //   bindings, set BASE to the binding at the end of the relation
+    //   chain (which will always be unconstrained), and set ADDEND to the
+    //   value to add to that binding's value to get this binding's
+    //   value.
+    // - If this binding is unconstrained, set BASE to this, and leave
+    //   ADDEND unchanged.
+    void Get(Binding** base, uint64_t* addend);
+
+   private:
+    // There are three cases:
+    //
+    // - A binding representing a known constant value has base_ NULL,
+    //   and addend_ equal to the value.
+    //
+    // - A binding representing a completely unconstrained value has
+    //   base_ pointing to this; addend_ is unused.
+    //
+    // - A binding whose value is related to some other binding's
+    //   value has base_ pointing to that other binding, and addend_
+    //   set to the amount to add to that binding's value to get this
+    //   binding's value. We only represent relationships of the form
+    //   x = y+c.
+    //
+    // Thus, the bind_ links form a chain terminating in either a
+    // known constant value or a completely unconstrained value. Most
+    // operations on bindings do path compression: they change every
+    // binding on the chain to point directly to the final value,
+    // adjusting addends as appropriate.
+    Binding* base_;
+    uint64_t addend_;
+
+    // The number of Labels and Bindings pointing to this binding.
+    // (When a binding points to itself, indicating a completely
+    // unconstrained binding, that doesn't count as a reference.)
+    int reference_count_;
+  };
+
+  // This label's value.
+  Binding* value_;
+};
+
+// Conventions for representing larger numbers as sequences of bytes.
+enum Endianness {
+  kBigEndian,     // Big-endian: the most significant byte comes first.
+  kLittleEndian,  // Little-endian: the least significant byte comes first.
+  kUnsetEndian,   // used internally
+};
+
+// A section is a sequence of bytes, constructed by appending bytes
+// to the end. Sections have a convenient and flexible set of member
+// functions for appending data in various formats: big-endian and
+// little-endian signed and unsigned values of different sizes;
+// LEB128 and ULEB128 values (see below), and raw blocks of bytes.
+//
+// If you need to append a value to a section that is not convenient
+// to compute immediately, you can create a label, append the
+// label's value to the section, and then set the label's value
+// later, when it's convenient to do so. Once a label's value is
+// known, the section class takes care of updating all previously
+// appended references to it.
+//
+// Once all the labels to which a section refers have had their
+// values determined, you can get a copy of the section's contents
+// as a string.
+//
+// Note that there is no specified "start of section" label. This is
+// because there are typically several different meanings for "the
+// start of a section": the offset of the section within an object
+// file, the address in memory at which the section's content appear,
+// and so on. It's up to the code that uses the Section class to
+// keep track of these explicitly, as they depend on the application.
+class Section {
+ public:
+  explicit Section(Endianness endianness = kUnsetEndian)
+      : endianness_(endianness){};
+
+  // A base class destructor should be either public and virtual,
+  // or protected and nonvirtual.
+  virtual ~Section(){};
+
+  // Return the default endianness of this section.
+  Endianness endianness() const { return endianness_; }
+
+  // Append the SIZE bytes at DATA to the end of this section. Return
+  // a reference to this section.
+  Section& Append(const string& data) {
+    contents_.append(data);
+    return *this;
+  };
+
+  // Append data from SLICE to the end of this section. Return
+  // a reference to this section.
+  Section& Append(const lul::ImageSlice& slice) {
+    for (size_t i = 0; i < slice.length_; i++) {
+      contents_.append(1, slice.start_[i]);
+    }
+    return *this;
+  }
+
+  // Append data from CSTRING to the end of this section.  The terminating
+  // zero is not included.  Return a reference to this section.
+  Section& Append(const char* cstring) {
+    for (size_t i = 0; cstring[i] != '\0'; i++) {
+      contents_.append(1, cstring[i]);
+    }
+    return *this;
+  }
+
+  // Append SIZE copies of BYTE to the end of this section. Return a
+  // reference to this section.
+  Section& Append(size_t size, uint8_t byte) {
+    contents_.append(size, (char)byte);
+    return *this;
+  }
+
+  // Append NUMBER to this section. ENDIANNESS is the endianness to
+  // use to write the number. SIZE is the length of the number in
+  // bytes. Return a reference to this section.
+  Section& Append(Endianness endianness, size_t size, uint64_t number);
+  Section& Append(Endianness endianness, size_t size, const Label& label);
+
+  // Append SECTION to the end of this section. The labels SECTION
+  // refers to need not be defined yet.
+  //
+  // Note that this has no effect on any Labels' values, or on
+  // SECTION. If placing SECTION within 'this' provides new
+  // constraints on existing labels' values, then it's up to the
+  // caller to fiddle with those labels as needed.
+  Section& Append(const Section& section);
+
+  // Append the contents of DATA as a series of bytes terminated by
+  // a NULL character.
+  Section& AppendCString(const string& data) {
+    Append(data);
+    contents_ += '\0';
+    return *this;
+  }
+
+  // Append VALUE or LABEL to this section, with the given bit width and
+  // endianness. Return a reference to this section.
+  //
+  // The names of these functions have the form <ENDIANNESS><BITWIDTH>:
+  // <ENDIANNESS> is either 'L' (little-endian, least significant byte first),
+  //                        'B' (big-endian, most significant byte first), or
+  //                        'D' (default, the section's default endianness)
+  // <BITWIDTH> is 8, 16, 32, or 64.
+  //
+  // Since endianness doesn't matter for a single byte, all the
+  // <BITWIDTH>=8 functions are equivalent.
+  //
+  // These can be used to write both signed and unsigned values, as
+  // the compiler will properly sign-extend a signed value before
+  // passing it to the function, at which point the function's
+  // behavior is the same either way.
+  Section& L8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section& B8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section& D8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section &L16(uint16_t), &L32(uint32_t), &L64(uint64_t), &B16(uint16_t),
+      &B32(uint32_t), &B64(uint64_t), &D16(uint16_t), &D32(uint32_t),
+      &D64(uint64_t);
+  Section &L8(const Label&label), &L16(const Label&label),
+      &L32(const Label&label), &L64(const Label&label), &B8(const Label&label),
+      &B16(const Label&label), &B32(const Label&label), &B64(const Label&label),
+      &D8(const Label&label), &D16(const Label&label), &D32(const Label&label),
+      &D64(const Label&label);
+
+  // Append VALUE in a signed LEB128 (Little-Endian Base 128) form.
+  //
+  // The signed LEB128 representation of an integer N is a variable
+  // number of bytes:
+  //
+  // - If N is between -0x40 and 0x3f, then its signed LEB128
+  //   representation is a single byte whose value is N.
+  //
+  // - Otherwise, its signed LEB128 representation is (N & 0x7f) |
+  //   0x80, followed by the signed LEB128 representation of N / 128,
+  //   rounded towards negative infinity.
+  //
+  // In other words, we break VALUE into groups of seven bits, put
+  // them in little-endian order, and then write them as eight-bit
+  // bytes with the high bit on all but the last.
+  //
+  // Note that VALUE cannot be a Label (we would have to implement
+  // relaxation).
+  Section& LEB128(long long value);
+
+  // Append VALUE in unsigned LEB128 (Little-Endian Base 128) form.
+  //
+  // The unsigned LEB128 representation of an integer N is a variable
+  // number of bytes:
+  //
+  // - If N is between 0 and 0x7f, then its unsigned LEB128
+  //   representation is a single byte whose value is N.
+  //
+  // - Otherwise, its unsigned LEB128 representation is (N & 0x7f) |
+  //   0x80, followed by the unsigned LEB128 representation of N /
+  //   128, rounded towards negative infinity.
+  //
+  // Note that VALUE cannot be a Label (we would have to implement
+  // relaxation).
+  Section& ULEB128(uint64_t value);
+
+  // Jump to the next location aligned on an ALIGNMENT-byte boundary,
+  // relative to the start of the section. Fill the gap with PAD_BYTE.
+  // ALIGNMENT must be a power of two. Return a reference to this
+  // section.
+  Section& Align(size_t alignment, uint8_t pad_byte = 0);
+
+  // Return the current size of the section.
+  size_t Size() const { return contents_.size(); }
+
+  // Return a label representing the start of the section.
+  //
+  // It is up to the user whether this label represents the section's
+  // position in an object file, the section's address in memory, or
+  // what have you; some applications may need both, in which case
+  // this simple-minded interface won't be enough. This class only
+  // provides a single start label, for use with the Here and Mark
+  // member functions.
+  //
+  // Ideally, we'd provide this in a subclass that actually knows more
+  // about the application at hand and can provide an appropriate
+  // collection of start labels. But then the appending member
+  // functions like Append and D32 would return a reference to the
+  // base class, not the derived class, and the chaining won't work.
+  // Since the only value here is in pretty notation, that's a fatal
+  // flaw.
+  Label start() const { return start_; }
+
+  // Return a label representing the point at which the next Appended
+  // item will appear in the section, relative to start().
+  Label Here() const { return start_ + Size(); }
+
+  // Set *LABEL to Here, and return a reference to this section.
+  Section& Mark(Label* label) {
+    *label = Here();
+    return *this;
+  }
+
+  // If there are no undefined label references left in this
+  // section, set CONTENTS to the contents of this section, as a
+  // string, and clear this section. Return true on success, or false
+  // if there were still undefined labels.
+  bool GetContents(string* contents);
+
+ private:
+  // Used internally. A reference to a label's value.
+  struct Reference {
+    Reference(size_t set_offset, Endianness set_endianness, size_t set_size,
+              const Label& set_label)
+        : offset(set_offset),
+          endianness(set_endianness),
+          size(set_size),
+          label(set_label) {}
+
+    // The offset of the reference within the section.
+    size_t offset;
+
+    // The endianness of the reference.
+    Endianness endianness;
+
+    // The size of the reference.
+    size_t size;
+
+    // The label to which this is a reference.
+    Label label;
+  };
+
+  // The default endianness of this section.
+  Endianness endianness_;
+
+  // The contents of the section.
+  string contents_;
+
+  // References to labels within those contents.
+  vector<Reference> references_;
+
+  // A label referring to the beginning of the section.
+  Label start_;
+};
+
+}  // namespace test_assembler
+}  // namespace lul_test
+
+namespace lul_test {
+
+using lul::DwarfPointerEncoding;
+using lul_test::test_assembler::Endianness;
+using lul_test::test_assembler::Label;
+using lul_test::test_assembler::Section;
+
+class CFISection : public Section {
+ public:
+  // CFI augmentation strings beginning with 'z', defined by the
+  // Linux/IA-64 C++ ABI, can specify interesting encodings for
+  // addresses appearing in FDE headers and call frame instructions (and
+  // for additional fields whose presence the augmentation string
+  // specifies). In particular, pointers can be specified to be relative
+  // to various base address: the start of the .text section, the
+  // location holding the address itself, and so on. These allow the
+  // frame data to be position-independent even when they live in
+  // write-protected pages. These variants are specified at the
+  // following two URLs:
+  //
+  // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/dwarfext.html
+  // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
+  //
+  // CFISection leaves the production of well-formed 'z'-augmented CIEs and
+  // FDEs to the user, but does provide EncodedPointer, to emit
+  // properly-encoded addresses for a given pointer encoding.
+  // EncodedPointer uses an instance of this structure to find the base
+  // addresses it should use; you can establish a default for all encoded
+  // pointers appended to this section with SetEncodedPointerBases.
+  struct EncodedPointerBases {
+    EncodedPointerBases() : cfi(), text(), data() {}
+
+    // The starting address of this CFI section in memory, for
+    // DW_EH_PE_pcrel. DW_EH_PE_pcrel pointers may only be used in data
+    // that has is loaded into the program's address space.
+    uint64_t cfi;
+
+    // The starting address of this file's .text section, for DW_EH_PE_textrel.
+    uint64_t text;
+
+    // The starting address of this file's .got or .eh_frame_hdr section,
+    // for DW_EH_PE_datarel.
+    uint64_t data;
+  };
+
+  // Create a CFISection whose endianness is ENDIANNESS, and where
+  // machine addresses are ADDRESS_SIZE bytes long. If EH_FRAME is
+  // true, use the .eh_frame format, as described by the Linux
+  // Standards Base Core Specification, instead of the DWARF CFI
+  // format.
+  CFISection(Endianness endianness, size_t address_size, bool eh_frame = false)
+      : Section(endianness),
+        address_size_(address_size),
+        eh_frame_(eh_frame),
+        pointer_encoding_(lul::DW_EH_PE_absptr),
+        encoded_pointer_bases_(),
+        entry_length_(NULL),
+        in_fde_(false) {
+    // The 'start', 'Here', and 'Mark' members of a CFISection all refer
+    // to section offsets.
+    start() = 0;
+  }
+
+  // Return this CFISection's address size.
+  size_t AddressSize() const { return address_size_; }
+
+  // Return true if this CFISection uses the .eh_frame format, or
+  // false if it contains ordinary DWARF CFI data.
+  bool ContainsEHFrame() const { return eh_frame_; }
+
+  // Use ENCODING for pointers in calls to FDEHeader and EncodedPointer.
+  void SetPointerEncoding(DwarfPointerEncoding encoding) {
+    pointer_encoding_ = encoding;
+  }
+
+  // Use the addresses in BASES as the base addresses for encoded
+  // pointers in subsequent calls to FDEHeader or EncodedPointer.
+  // This function makes a copy of BASES.
+  void SetEncodedPointerBases(const EncodedPointerBases& bases) {
+    encoded_pointer_bases_ = bases;
+  }
+
+  // Append a Common Information Entry header to this section with the
+  // given values. If dwarf64 is true, use the 64-bit DWARF initial
+  // length format for the CIE's initial length. Return a reference to
+  // this section. You should call FinishEntry after writing the last
+  // instruction for the CIE.
+  //
+  // Before calling this function, you will typically want to use Mark
+  // or Here to make a label to pass to FDEHeader that refers to this
+  // CIE's position in the section.
+  CFISection& CIEHeader(uint64_t code_alignment_factor,
+                        int data_alignment_factor,
+                        unsigned return_address_register, uint8_t version = 3,
+                        const string& augmentation = "", bool dwarf64 = false);
+
+  // Append a Frame Description Entry header to this section with the
+  // given values. If dwarf64 is true, use the 64-bit DWARF initial
+  // length format for the CIE's initial length. Return a reference to
+  // this section. You should call FinishEntry after writing the last
+  // instruction for the CIE.
+  //
+  // This function doesn't support entries that are longer than
+  // 0xffffff00 bytes. (The "initial length" is always a 32-bit
+  // value.) Nor does it support .debug_frame sections longer than
+  // 0xffffff00 bytes.
+  CFISection& FDEHeader(Label cie_pointer, uint64_t initial_location,
+                        uint64_t address_range, bool dwarf64 = false);
+
+  // Note the current position as the end of the last CIE or FDE we
+  // started, after padding with DW_CFA_nops for alignment. This
+  // defines the label representing the entry's length, cited in the
+  // entry's header. Return a reference to this section.
+  CFISection& FinishEntry();
+
+  // Append the contents of BLOCK as a DW_FORM_block value: an
+  // unsigned LEB128 length, followed by that many bytes of data.
+  CFISection& Block(const lul::ImageSlice& block) {
+    ULEB128(block.length_);
+    Append(block);
+    return *this;
+  }
+
+  // Append data from CSTRING as a DW_FORM_block value: an unsigned LEB128
+  // length, followed by that many bytes of data. The terminating zero is not
+  // included.
+  CFISection& Block(const char* cstring) {
+    ULEB128(strlen(cstring));
+    Append(cstring);
+    return *this;
+  }
+
+  // Append ADDRESS to this section, in the appropriate size and
+  // endianness. Return a reference to this section.
+  CFISection& Address(uint64_t address) {
+    Section::Append(endianness(), address_size_, address);
+    return *this;
+  }
+
+  // Append ADDRESS to this section, using ENCODING and BASES. ENCODING
+  // defaults to this section's default encoding, established by
+  // SetPointerEncoding. BASES defaults to this section's bases, set by
+  // SetEncodedPointerBases. If the DW_EH_PE_indirect bit is set in the
+  // encoding, assume that ADDRESS is where the true address is stored.
+  // Return a reference to this section.
+  //
+  // (C++ doesn't let me use default arguments here, because I want to
+  // refer to members of *this in the default argument expression.)
+  CFISection& EncodedPointer(uint64_t address) {
+    return EncodedPointer(address, pointer_encoding_, encoded_pointer_bases_);
+  }
+  CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding) {
+    return EncodedPointer(address, encoding, encoded_pointer_bases_);
+  }
+  CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding,
+                             const EncodedPointerBases& bases);
+
+  // Restate some member functions, to keep chaining working nicely.
+  CFISection& Mark(Label* label) {
+    Section::Mark(label);
+    return *this;
+  }
+  CFISection& D8(uint8_t v) {
+    Section::D8(v);
+    return *this;
+  }
+  CFISection& D16(uint16_t v) {
+    Section::D16(v);
+    return *this;
+  }
+  CFISection& D16(Label v) {
+    Section::D16(v);
+    return *this;
+  }
+  CFISection& D32(uint32_t v) {
+    Section::D32(v);
+    return *this;
+  }
+  CFISection& D32(const Label& v) {
+    Section::D32(v);
+    return *this;
+  }
+  CFISection& D64(uint64_t v) {
+    Section::D64(v);
+    return *this;
+  }
+  CFISection& D64(const Label& v) {
+    Section::D64(v);
+    return *this;
+  }
+  CFISection& LEB128(long long v) {
+    Section::LEB128(v);
+    return *this;
+  }
+  CFISection& ULEB128(uint64_t v) {
+    Section::ULEB128(v);
+    return *this;
+  }
+
+ private:
+  // A length value that we've appended to the section, but is not yet
+  // known. LENGTH is the appended value; START is a label referring
+  // to the start of the data whose length was cited.
+  struct PendingLength {
+    Label length;
+    Label start;
+  };
+
+  // Constants used in CFI/.eh_frame data:
+
+  // If the first four bytes of an "initial length" are this constant, then
+  // the data uses the 64-bit DWARF format, and the length itself is the
+  // subsequent eight bytes.
+  static const uint32_t kDwarf64InitialLengthMarker = 0xffffffffU;
+
+  // The CIE identifier for 32- and 64-bit DWARF CFI and .eh_frame data.
+  static const uint32_t kDwarf32CIEIdentifier = ~(uint32_t)0;
+  static const uint64_t kDwarf64CIEIdentifier = ~(uint64_t)0;
+  static const uint32_t kEHFrame32CIEIdentifier = 0;
+  static const uint64_t kEHFrame64CIEIdentifier = 0;
+
+  // The size of a machine address for the data in this section.
+  size_t address_size_;
+
+  // If true, we are generating a Linux .eh_frame section, instead of
+  // a standard DWARF .debug_frame section.
+  bool eh_frame_;
+
+  // The encoding to use for FDE pointers.
+  DwarfPointerEncoding pointer_encoding_;
+
+  // The base addresses to use when emitting encoded pointers.
+  EncodedPointerBases encoded_pointer_bases_;
+
+  // The length value for the current entry.
+  //
+  // Oddly, this must be dynamically allocated. Labels never get new
+  // values; they only acquire constraints on the value they already
+  // have, or assert if you assign them something incompatible. So
+  // each header needs truly fresh Label objects to cite in their
+  // headers and track their positions. The alternative is explicit
+  // destructor invocation and a placement new. Ick.
+  PendingLength* entry_length_;
+
+  // True if we are currently emitting an FDE --- that is, we have
+  // called FDEHeader but have not yet called FinishEntry.
+  bool in_fde_;
+
+  // If in_fde_ is true, this is its starting address. We use this for
+  // emitting DW_EH_PE_funcrel pointers.
+  uint64_t fde_start_address_;
+};
+
+}  // namespace lul_test
+
+#endif  // LUL_TEST_INFRASTRUCTURE_H
diff --git a/tools/profiler/tests/gtest/ThreadProfileTest.cpp b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
new file mode 100644
index 0000000000..b8a15c39b2
--- /dev/null
+++ b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
@@ -0,0 +1,60 @@
+
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifdef MOZ_GECKO_PROFILER
+
+#  include "ProfileBuffer.h"
+
+#  include "mozilla/PowerOfTwo.h"
+#  include "mozilla/ProfileBufferChunkManagerWithLocalLimit.h"
+#  include "mozilla/ProfileChunkedBuffer.h"
+
+#  include "gtest/gtest.h"
+
+// Make sure we can record one entry and read it
+TEST(ThreadProfile, InsertOneEntry)
+{
+  mozilla::ProfileBufferChunkManagerWithLocalLimit chunkManager(
+      2 * (1 + uint32_t(sizeof(ProfileBufferEntry))) * 4,
+      2 * (1 + uint32_t(sizeof(ProfileBufferEntry))));
+  mozilla::ProfileChunkedBuffer profileChunkedBuffer(
+      mozilla::ProfileChunkedBuffer::ThreadSafety::WithMutex, chunkManager);
+  auto pb = mozilla::MakeUnique<ProfileBuffer>(profileChunkedBuffer);
+  pb->AddEntry(ProfileBufferEntry::Time(123.1));
+  ProfileBufferEntry entry = pb->GetEntry(pb->BufferRangeStart());
+  ASSERT_TRUE(entry.IsTime());
+  ASSERT_EQ(123.1, entry.GetDouble());
+}
+
+// See if we can insert some entries
+TEST(ThreadProfile, InsertEntriesNoWrap)
+{
+  mozilla::ProfileBufferChunkManagerWithLocalLimit chunkManager(
+      100 * (1 + uint32_t(sizeof(ProfileBufferEntry))),
+      100 * (1 + uint32_t(sizeof(ProfileBufferEntry))) / 4);
+  mozilla::ProfileChunkedBuffer profileChunkedBuffer(
+      mozilla::ProfileChunkedBuffer::ThreadSafety::WithMutex, chunkManager);
+  auto pb = mozilla::MakeUnique<ProfileBuffer>(profileChunkedBuffer);
+  const int test_size = 50;
+  for (int i = 0; i < test_size; i++) {
+    pb->AddEntry(ProfileBufferEntry::Time(i));
+  }
+  int times = 0;
+  uint64_t readPos = pb->BufferRangeStart();
+  while (readPos != pb->BufferRangeEnd()) {
+    ProfileBufferEntry entry = pb->GetEntry(readPos);
+    readPos++;
+    if (entry.GetKind() == ProfileBufferEntry::Kind::INVALID) {
+      continue;
+    }
+    ASSERT_TRUE(entry.IsTime());
+    ASSERT_EQ(times, entry.GetDouble());
+    times++;
+  }
+  ASSERT_EQ(test_size, times);
+}
+
+#endif  // MOZ_GECKO_PROFILER
diff --git a/tools/profiler/tests/gtest/moz.build b/tools/profiler/tests/gtest/moz.build
new file mode 100644
index 0000000000..4eb1fef762
--- /dev/null
+++ b/tools/profiler/tests/gtest/moz.build
@@ -0,0 +1,45 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, you can obtain one at http://mozilla.org/MPL/2.0/.
+
+if (
+    CONFIG["MOZ_GECKO_PROFILER"]
+    and CONFIG["OS_TARGET"] in ("Android", "Linux")
+    and CONFIG["CPU_ARCH"]
+    in (
+        "arm",
+        "aarch64",
+        "x86",
+        "x86_64",
+    )
+):
+    UNIFIED_SOURCES += [
+        "LulTest.cpp",
+        "LulTestDwarf.cpp",
+        "LulTestInfrastructure.cpp",
+    ]
+
+LOCAL_INCLUDES += [
+    "/netwerk/base",
+    "/netwerk/protocol/http",
+    "/toolkit/components/jsoncpp/include",
+    "/tools/profiler/core",
+    "/tools/profiler/gecko",
+    "/tools/profiler/lul",
+]
+
+if CONFIG["OS_TARGET"] != "Android":
+    UNIFIED_SOURCES += [
+        "GeckoProfiler.cpp",
+        "ThreadProfileTest.cpp",
+    ]
+
+USE_LIBS += [
+    "jsoncpp",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul-gtest"
diff --git a/tools/profiler/tests/shared-head.js b/tools/profiler/tests/shared-head.js
new file mode 100644
index 0000000000..3b18934d01
--- /dev/null
+++ b/tools/profiler/tests/shared-head.js
@@ -0,0 +1,568 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals Assert */
+
+/**
+ * This file contains utilities that can be shared between xpcshell tests and mochitests.
+ */
+
+// The marker phases.
+const INSTANT = 0;
+const INTERVAL = 1;
+const INTERVAL_START = 2;
+const INTERVAL_END = 3;
+
+// This Services declaration may shadow another from head.js, so define it as
+// a var rather than a const.
+
+const defaultSettings = {
+  entries: 8 * 1024 * 1024, // 8M entries = 64MB
+  interval: 1, // ms
+  features: [],
+  threads: ["GeckoMain"],
+};
+
+// Effectively `async`: Start the profiler and return the `startProfiler`
+// promise that will get resolved when all child process have started their own
+// profiler.
+function startProfiler(callersSettings) {
+  if (Services.profiler.IsActive()) {
+    throw new Error(
+      "The profiler must not be active before starting it in a test."
+    );
+  }
+  const settings = Object.assign({}, defaultSettings, callersSettings);
+  return Services.profiler.StartProfiler(
+    settings.entries,
+    settings.interval,
+    settings.features,
+    settings.threads,
+    0,
+    settings.duration
+  );
+}
+
+function startProfilerForMarkerTests() {
+  return startProfiler({
+    features: ["nostacksampling", "js"],
+    threads: ["GeckoMain", "DOM Worker"],
+  });
+}
+
+/**
+ * This is a helper function be able to run `await wait(500)`. Unfortunately
+ * this is needed as the act of collecting functions relies on the periodic
+ * sampling of the threads. See:
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=1529053
+ *
+ * @param {number} time
+ * @returns {Promise}
+ */
+function wait(time) {
+  return new Promise(resolve => {
+    // eslint-disable-next-line mozilla/no-arbitrary-setTimeout
+    setTimeout(resolve, time);
+  });
+}
+
+/**
+ * Get the payloads of a type recursively, including from all subprocesses.
+ *
+ * @param {Object} profile The gecko profile.
+ * @param {string} type The marker payload type, e.g. "DiskIO".
+ * @param {Array} payloadTarget The recursive list of payloads.
+ * @return {Array} The final payloads.
+ */
+function getPayloadsOfTypeFromAllThreads(profile, type, payloadTarget = []) {
+  for (const { markers } of profile.threads) {
+    for (const markerTuple of markers.data) {
+      const payload = markerTuple[markers.schema.data];
+      if (payload && payload.type === type) {
+        payloadTarget.push(payload);
+      }
+    }
+  }
+
+  for (const subProcess of profile.processes) {
+    getPayloadsOfTypeFromAllThreads(subProcess, type, payloadTarget);
+  }
+
+  return payloadTarget;
+}
+
+/**
+ * Get the payloads of a type from a single thread.
+ *
+ * @param {Object} thread The thread from a profile.
+ * @param {string} type The marker payload type, e.g. "DiskIO".
+ * @return {Array} The payloads.
+ */
+function getPayloadsOfType(thread, type) {
+  const { markers } = thread;
+  const results = [];
+  for (const markerTuple of markers.data) {
+    const payload = markerTuple[markers.schema.data];
+    if (payload && payload.type === type) {
+      results.push(payload);
+    }
+  }
+  return results;
+}
+
+/**
+ * Applies the marker schema to create individual objects for each marker
+ *
+ * @param {Object} thread The thread from a profile.
+ * @return {InflatedMarker[]} The markers.
+ */
+function getInflatedMarkerData(thread) {
+  const { markers, stringTable } = thread;
+  return markers.data.map(markerTuple => {
+    const marker = {};
+    for (const [key, tupleIndex] of Object.entries(markers.schema)) {
+      marker[key] = markerTuple[tupleIndex];
+      if (key === "name") {
+        // Use the string from the string table.
+        marker[key] = stringTable[marker[key]];
+      }
+    }
+    return marker;
+  });
+}
+
+/**
+ * Applies the marker schema to create individual objects for each marker, then
+ * keeps only the network markers that match the profiler tests.
+ *
+ * @param {Object} thread The thread from a profile.
+ * @return {InflatedMarker[]} The filtered network markers.
+ */
+function getInflatedNetworkMarkers(thread) {
+  const markers = getInflatedMarkerData(thread);
+  return markers.filter(
+    m =>
+      m.data &&
+      m.data.type === "Network" &&
+      // We filter out network markers that aren't related to the test, to
+      // avoid intermittents.
+      m.data.URI.includes("/tools/profiler/")
+  );
+}
+
+/**
+ * From a list of network markers, this returns pairs of start/stop markers.
+ * If a stop marker can't be found for a start marker, this will return an array
+ * of only 1 element.
+ *
+ * @param {InflatedMarker[]} networkMarkers Network markers
+ * @return {InflatedMarker[][]} Pairs of network markers
+ */
+function getPairsOfNetworkMarkers(allNetworkMarkers) {
+  // For each 'start' marker we want to find the next 'stop' or 'redirect'
+  // marker with the same id.
+  const result = [];
+  const mapOfStartMarkers = new Map(); // marker id -> id in result array
+  for (const marker of allNetworkMarkers) {
+    const { data } = marker;
+    if (data.status === "STATUS_START") {
+      if (mapOfStartMarkers.has(data.id)) {
+        const previousMarker = result[mapOfStartMarkers.get(data.id)][0];
+        Assert.ok(
+          false,
+          `We found 2 start markers with the same id ${data.id}, without end marker in-between.` +
+            `The first marker has URI ${previousMarker.data.URI}, the second marker has URI ${data.URI}.` +
+            ` This should not happen.`
+        );
+        continue;
+      }
+
+      mapOfStartMarkers.set(data.id, result.length);
+      result.push([marker]);
+    } else {
+      // STOP or REDIRECT
+      if (!mapOfStartMarkers.has(data.id)) {
+        Assert.ok(
+          false,
+          `We found an end marker without a start marker (id: ${data.id}, URI: ${data.URI}). This should not happen.`
+        );
+        continue;
+      }
+      result[mapOfStartMarkers.get(data.id)].push(marker);
+      mapOfStartMarkers.delete(data.id);
+    }
+  }
+
+  return result;
+}
+
+/**
+ * It can be helpful to force the profiler to collect a JavaScript sample. This
+ * function spins on a while loop until at least one more sample is collected.
+ *
+ * @return {number} The index of the collected sample.
+ */
+function captureAtLeastOneJsSample() {
+  function getProfileSampleCount() {
+    const profile = Services.profiler.getProfileData();
+    return profile.threads[0].samples.data.length;
+  }
+
+  const sampleCount = getProfileSampleCount();
+  // Create an infinite loop until a sample has been collected.
+  while (true) {
+    if (sampleCount < getProfileSampleCount()) {
+      return sampleCount;
+    }
+  }
+}
+
+function isJSONWhitespace(c) {
+  return ["\n", "\r", " ", "\t"].includes(c);
+}
+
+function verifyJSONStringIsCompact(s) {
+  const stateData = 0;
+  const stateString = 1;
+  const stateEscapedChar = 2;
+  let state = stateData;
+  for (let i = 0; i < s.length; ++i) {
+    let c = s[i];
+    switch (state) {
+      case stateData:
+        if (isJSONWhitespace(c)) {
+          Assert.ok(
+            false,
+            `"Unexpected JSON whitespace at index ${i} in profile: <<<${s}>>>"`
+          );
+          return;
+        }
+        if (c == '"') {
+          state = stateString;
+        }
+        break;
+      case stateString:
+        if (c == '"') {
+          state = stateData;
+        } else if (c == "\\") {
+          state = stateEscapedChar;
+        }
+        break;
+      case stateEscapedChar:
+        state = stateString;
+        break;
+    }
+  }
+}
+
+/**
+ * This function pauses the profiler before getting the profile. Then after
+ * getting the data, the profiler is stopped, and all profiler data is removed.
+ * @returns {Promise<Profile>}
+ */
+async function stopNowAndGetProfile() {
+  // Don't await the pause, because each process will handle it before it
+  // receives the following `getProfileDataAsArrayBuffer()`.
+  Services.profiler.Pause();
+
+  const profileArrayBuffer = await Services.profiler.getProfileDataAsArrayBuffer();
+  await Services.profiler.StopProfiler();
+
+  const profileUint8Array = new Uint8Array(profileArrayBuffer);
+  const textDecoder = new TextDecoder("utf-8", { fatal: true });
+  const profileString = textDecoder.decode(profileUint8Array);
+  verifyJSONStringIsCompact(profileString);
+
+  return JSON.parse(profileString);
+}
+
+/**
+ * This function ensures there's at least one sample, then pauses the profiler
+ * before getting the profile. Then after getting the data, the profiler is
+ * stopped, and all profiler data is removed.
+ * @returns {Promise<Profile>}
+ */
+async function waitSamplingAndStopAndGetProfile() {
+  await Services.profiler.waitOnePeriodicSampling();
+  return stopNowAndGetProfile();
+}
+
+/**
+ * Verifies that a marker is an interval marker.
+ *
+ * @param {InflatedMarker} marker
+ * @returns {boolean}
+ */
+function isIntervalMarker(inflatedMarker) {
+  return (
+    inflatedMarker.phase === 1 &&
+    typeof inflatedMarker.startTime === "number" &&
+    typeof inflatedMarker.endTime === "number"
+  );
+}
+
+/**
+ * @param {Profile} profile
+ * @returns {Thread[]}
+ */
+function getThreads(profile) {
+  const threads = [];
+
+  function getThreadsRecursive(process) {
+    for (const thread of process.threads) {
+      threads.push(thread);
+    }
+    for (const subprocess of process.processes) {
+      getThreadsRecursive(subprocess);
+    }
+  }
+
+  getThreadsRecursive(profile);
+  return threads;
+}
+
+/**
+ * Find a specific marker schema from any process of a profile.
+ *
+ * @param {Profile} profile
+ * @param {string} name
+ * @returns {MarkerSchema}
+ */
+function getSchema(profile, name) {
+  {
+    const schema = profile.meta.markerSchema.find(s => s.name === name);
+    if (schema) {
+      return schema;
+    }
+  }
+  for (const subprocess of profile.processes) {
+    const schema = subprocess.meta.markerSchema.find(s => s.name === name);
+    if (schema) {
+      return schema;
+    }
+  }
+  console.error("Parent process schema", profile.meta.markerSchema);
+  for (const subprocess of profile.processes) {
+    console.error("Child process schema", subprocess.meta.markerSchema);
+  }
+  throw new Error(`Could not find a schema for "${name}".`);
+}
+
+/**
+ * This escapes all characters that have a special meaning in RegExps.
+ * This was stolen from https://github.com/sindresorhus/escape-string-regexp and
+ * so it is licence MIT and:
+ * Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (https://sindresorhus.com).
+ * See the full license in https://raw.githubusercontent.com/sindresorhus/escape-string-regexp/main/license.
+ * @param {string} string The string to be escaped
+ * @returns {string} The result
+ */
+function escapeStringRegexp(string) {
+  if (typeof string !== "string") {
+    throw new TypeError("Expected a string");
+  }
+
+  // Escape characters with special meaning either inside or outside character
+  // sets.  Use a simple backslash escape when it’s always valid, and a `\xnn`
+  // escape when the simpler form would be disallowed by Unicode patterns’
+  // stricter grammar.
+  return string.replace(/[|\\{}()[\]^$+*?.]/g, "\\$&").replace(/-/g, "\\x2d");
+}
+
+/** ------ Assertions helper ------ */
+/**
+ * This assert helper function makes it easy to check a lot of properties in an
+ * object. We augment Assert.sys.mjs to make it easier to use.
+ */
+Object.assign(Assert, {
+  /*
+   * It checks if the properties on the right are all present in the object on
+   * the left. Note that the object might still have other properties (see
+   * objectContainsOnly below if you want the stricter form).
+   *
+   * The basic form does basic equality on each expected property:
+   *
+   * Assert.objectContains(fixture, {
+   *   foo: "foo",
+   *   bar: 1,
+   *   baz: true,
+   * });
+   *
+   * But it also has a more powerful form with expectations. The available
+   * expectations are:
+   * - any(): this only checks for the existence of the property, not its value
+   * - number(), string(), boolean(), bigint(), function(), symbol(), object():
+   *   this checks if the value is of this type
+   * - objectContains(expected): this applies Assert.objectContains()
+   *   recursively on this property.
+   * - stringContains(needle): this checks if the expected value is included in
+   *   the property value.
+   * - stringMatches(regexp): this checks if the property value matches this
+   *   regexp. The regexp can be passed as a string, to be dynamically built.
+   *
+   * example:
+   *
+   * Assert.objectContains(fixture, {
+   *   name: Expect.stringMatches(`Load \\d+:.*${url}`),
+   *   data: Expect.objectContains({
+   *     status: "STATUS_STOP",
+   *     URI: Expect.stringContains("https://"),
+   *     requestMethod: "GET",
+   *     contentType: Expect.string(),
+   *     startTime: Expect.number(),
+   *     cached: Expect.boolean(),
+   *   }),
+   * });
+   *
+   * Each expectation will translate into one or more Assert call. Therefore if
+   * one expectation fails, this will be clearly visible in the test output.
+   *
+   * Expectations can also be normal functions, for example:
+   *
+   * Assert.objectContains(fixture, {
+   *   number: value => Assert.greater(value, 5)
+   * });
+   *
+   * Note that you'll need to use Assert inside this function.
+   */
+  objectContains(object, expectedProperties) {
+    // Basic tests: we don't want to run other assertions if these tests fail.
+    if (typeof object !== "object") {
+      this.ok(
+        false,
+        `The first parameter should be an object, but found: ${object}.`
+      );
+      return;
+    }
+
+    if (typeof expectedProperties !== "object") {
+      this.ok(
+        false,
+        `The second parameter should be an object, but found: ${expectedProperties}.`
+      );
+      return;
+    }
+
+    for (const key of Object.keys(expectedProperties)) {
+      const expected = expectedProperties[key];
+      if (!(key in object)) {
+        this.report(
+          true,
+          object,
+          expectedProperties,
+          `The object should contain the property "${key}", but it's missing.`
+        );
+        continue;
+      }
+
+      if (typeof expected === "function") {
+        // This is a function, so let's call it.
+        expected(
+          object[key],
+          `The object should contain the property "${key}" with an expected value and type.`
+        );
+      } else {
+        // Otherwise, we check for equality.
+        this.equal(
+          object[key],
+          expectedProperties[key],
+          `The object should contain the property "${key}" with an expected value.`
+        );
+      }
+    }
+  },
+
+  /**
+   * This is very similar to the previous `objectContains`, but this also looks
+   * at the number of the objects' properties. Thus this will fail if the
+   * objects don't have the same properties exactly.
+   */
+  objectContainsOnly(object, expectedProperties) {
+    // Basic tests: we don't want to run other assertions if these tests fail.
+    if (typeof object !== "object") {
+      this.ok(
+        false,
+        `The first parameter should be an object but found: ${object}.`
+      );
+      return;
+    }
+
+    if (typeof expectedProperties !== "object") {
+      this.ok(
+        false,
+        `The second parameter should be an object but found: ${expectedProperties}.`
+      );
+      return;
+    }
+
+    // In objectContainsOnly, we specifically want to check if all properties
+    // from the fixture object are expected.
+    // We'll be failing a test only for the specific properties that weren't
+    // expected, and only fail with one message, so that the test outputs aren't
+    // spammed.
+    const extraProperties = [];
+    for (const fixtureKey of Object.keys(object)) {
+      if (!(fixtureKey in expectedProperties)) {
+        extraProperties.push(fixtureKey);
+      }
+    }
+
+    if (extraProperties.length) {
+      // Some extra properties have been found.
+      this.report(
+        true,
+        object,
+        expectedProperties,
+        `These properties are present, but shouldn't: "${extraProperties.join(
+          '", "'
+        )}".`
+      );
+    }
+
+    // Now, let's carry on the rest of our work.
+    this.objectContains(object, expectedProperties);
+  },
+});
+
+const Expect = {
+  any: () => actual => {} /* We don't check anything more than the presence of this property. */,
+};
+
+/* These functions are part of the Assert object, and we want to reuse them. */
+[
+  "stringContains",
+  "stringMatches",
+  "objectContains",
+  "objectContainsOnly",
+].forEach(
+  assertChecker =>
+    (Expect[assertChecker] = expected => (actual, ...moreArgs) =>
+      Assert[assertChecker](actual, expected, ...moreArgs))
+);
+
+/* These functions will only check for the type. */
+[
+  "number",
+  "string",
+  "boolean",
+  "bigint",
+  "symbol",
+  "object",
+  "function",
+].forEach(type => (Expect[type] = makeTypeChecker(type)));
+
+function makeTypeChecker(type) {
+  return (...unexpectedArgs) => {
+    if (unexpectedArgs.length) {
+      throw new Error(
+        "Type checkers expectations aren't expecting any argument."
+      );
+    }
+    return (actual, message) => {
+      const isCorrect = typeof actual === type;
+      Assert.report(!isCorrect, actual, type, message, "has type");
+    };
+  };
+}
+/* ------ End of assertion helper ------ */
diff --git a/tools/profiler/tests/xpcshell/head.js b/tools/profiler/tests/xpcshell/head.js
new file mode 100644
index 0000000000..ce87b32fd5
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/head.js
@@ -0,0 +1,244 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* import-globals-from ../shared-head.js */
+
+// This Services declaration may shadow another from head.js, so define it as
+// a var rather than a const.
+
+const { AppConstants } = ChromeUtils.importESModule(
+  "resource://gre/modules/AppConstants.sys.mjs"
+);
+const { setTimeout } = ChromeUtils.importESModule(
+  "resource://gre/modules/Timer.sys.mjs"
+);
+
+// Load the shared head
+const sharedHead = do_get_file("shared-head.js", false);
+if (!sharedHead) {
+  throw new Error("Could not load the shared head.");
+}
+Services.scriptloader.loadSubScript(
+  Services.io.newFileURI(sharedHead).spec,
+  this
+);
+
+/**
+ * This function takes a thread, and a sample tuple from the "data" array, and
+ * inflates the frame to be an array of strings.
+ *
+ * @param {Object} thread - The thread from the profile.
+ * @param {Array} sample - The tuple from the thread.samples.data array.
+ * @returns {Array<string>} An array of function names.
+ */
+function getInflatedStackLocations(thread, sample) {
+  let stackTable = thread.stackTable;
+  let frameTable = thread.frameTable;
+  let stringTable = thread.stringTable;
+  let SAMPLE_STACK_SLOT = thread.samples.schema.stack;
+  let STACK_PREFIX_SLOT = stackTable.schema.prefix;
+  let STACK_FRAME_SLOT = stackTable.schema.frame;
+  let FRAME_LOCATION_SLOT = frameTable.schema.location;
+
+  // Build the stack from the raw data and accumulate the locations in
+  // an array.
+  let stackIndex = sample[SAMPLE_STACK_SLOT];
+  let locations = [];
+  while (stackIndex !== null) {
+    let stackEntry = stackTable.data[stackIndex];
+    let frame = frameTable.data[stackEntry[STACK_FRAME_SLOT]];
+    locations.push(stringTable[frame[FRAME_LOCATION_SLOT]]);
+    stackIndex = stackEntry[STACK_PREFIX_SLOT];
+  }
+
+  // The profiler tree is inverted, so reverse the array.
+  return locations.reverse();
+}
+
+/**
+ * This utility matches up stacks to see if they contain a certain sequence of
+ * stack frames. A correctly functioning profiler will have a certain sequence
+ * of stacks, but we can't always determine exactly which stacks will show up
+ * due to implementation changes, as well as memory addresses being arbitrary to
+ * that particular build.
+ *
+ * This function triggers a test failure with a nice debug message when it
+ * fails.
+ *
+ * @param {Array<string>} actualStackFrames - As generated by
+ *     inflatedStackFrames.
+ * @param {Array<string | RegExp>} expectedStackFrames - Matches a subset of
+ *     actualStackFrames
+ */
+function expectStackToContain(
+  actualStackFrames,
+  expectedStackFrames,
+  message = "The actual stack and expected stack do not match."
+) {
+  // Log the stacks that are being passed to this assertion, as it could be
+  // useful for when these tests fail.
+  console.log("Actual stack: ", actualStackFrames);
+  console.log(
+    "Expected to contain: ",
+    expectedStackFrames.map(s => s.toString())
+  );
+
+  let actualIndex = 0;
+
+  // Start walking the expected stack and look for matches.
+  for (
+    let expectedIndex = 0;
+    expectedIndex < expectedStackFrames.length;
+    expectedIndex++
+  ) {
+    const expectedStackFrame = expectedStackFrames[expectedIndex];
+
+    while (true) {
+      // Make sure that we haven't run out of actual stack frames.
+      if (actualIndex >= actualStackFrames.length) {
+        info(`Could not find a match for: "${expectedStackFrame.toString()}"`);
+        Assert.ok(false, message);
+      }
+
+      const actualStackFrame = actualStackFrames[actualIndex];
+      actualIndex++;
+
+      const itMatches =
+        typeof expectedStackFrame === "string"
+          ? expectedStackFrame === actualStackFrame
+          : actualStackFrame.match(expectedStackFrame);
+
+      if (itMatches) {
+        // We found a match, break out of this loop.
+        break;
+      }
+      // Keep on looping looking for a match.
+    }
+  }
+
+  Assert.ok(true, message);
+}
+
+/**
+ * @param {Thread} thread
+ * @param {string} filename - The filename used to trigger FileIO.
+ * @returns {InflatedMarkers[]}
+ */
+function getInflatedFileIOMarkers(thread, filename) {
+  const markers = getInflatedMarkerData(thread);
+  return markers.filter(
+    marker =>
+      marker.data?.type === "FileIO" &&
+      marker.data?.filename?.endsWith(filename)
+  );
+}
+
+/**
+ * Checks properties common to all FileIO markers.
+ *
+ * @param {InflatedMarkers[]} markers
+ * @param {string} filename
+ */
+function checkInflatedFileIOMarkers(markers, filename) {
+  greater(markers.length, 0, "Found some markers");
+
+  // See IOInterposeObserver::Observation::ObservedOperationString
+  const validOperations = new Set([
+    "write",
+    "fsync",
+    "close",
+    "stat",
+    "create/open",
+    "read",
+  ]);
+  const validSources = new Set(["PoisonIOInterposer", "NSPRIOInterposer"]);
+
+  for (const marker of markers) {
+    try {
+      ok(
+        marker.name.startsWith("FileIO"),
+        "Has a marker.name that starts with FileIO"
+      );
+      equal(marker.data.type, "FileIO", "Has a marker.data.type");
+      ok(isIntervalMarker(marker), "All FileIO markers are interval markers");
+      ok(
+        validOperations.has(marker.data.operation),
+        `The markers have a known operation - "${marker.data.operation}"`
+      );
+      ok(
+        validSources.has(marker.data.source),
+        `The FileIO marker has a known source "${marker.data.source}"`
+      );
+      ok(marker.data.filename.endsWith(filename));
+      ok(Boolean(marker.data.stack), "A stack was collected");
+    } catch (error) {
+      console.error("Failing inflated FileIO marker:", marker);
+      throw error;
+    }
+  }
+}
+
+/**
+ * Do deep equality checks for schema, but then surface nice errors for a user to know
+ * what to do if the check fails.
+ */
+function checkSchema(actual, expected) {
+  const schemaName = expected.name;
+  info(`Checking marker schema for "${schemaName}"`);
+
+  try {
+    ok(
+      actual,
+      `Schema was found for "${schemaName}". See the test output for more information.`
+    );
+    // Check individual properties to surface easier to debug errors.
+    deepEqual(
+      expected.display,
+      actual.display,
+      `The "display" property for ${schemaName} schema matches. See the test output for more information.`
+    );
+    if (expected.data) {
+      ok(actual.data, `Schema was found for "${schemaName}"`);
+      for (const expectedDatum of expected.data) {
+        const actualDatum = actual.data.find(d => d.key === expectedDatum.key);
+        deepEqual(
+          expectedDatum,
+          actualDatum,
+          `The "${schemaName}" field "${expectedDatum.key}" matches expectations. See the test output for more information.`
+        );
+      }
+      equal(
+        expected.data.length,
+        actual.data.length,
+        "The expected and actual data have the same number of items"
+      );
+    }
+
+    // Finally do a true deep equal.
+    deepEqual(expected, actual, "The entire schema is deepEqual");
+  } catch (error) {
+    // The test results are not very human readable. This is a bit of a hacky
+    // solution to make it more readable.
+    dump("-----------------------------------------------------\n");
+    dump("The expected marker schema:\n");
+    dump("-----------------------------------------------------\n");
+    dump(JSON.stringify(expected, null, 2));
+    dump("\n");
+    dump("-----------------------------------------------------\n");
+    dump("The actual marker schema:\n");
+    dump("-----------------------------------------------------\n");
+    dump(JSON.stringify(actual, null, 2));
+    dump("\n");
+    dump("-----------------------------------------------------\n");
+    dump("A marker schema was not equal to expectations. If you\n");
+    dump("are modifying the schema, then please copy and paste\n");
+    dump("the new schema into this test.\n");
+    dump("-----------------------------------------------------\n");
+    dump("Copy this: " + JSON.stringify(actual));
+    dump("\n");
+    dump("-----------------------------------------------------\n");
+
+    throw error;
+  }
+}
diff --git a/tools/profiler/tests/xpcshell/test_active_configuration.js b/tools/profiler/tests/xpcshell/test_active_configuration.js
new file mode 100644
index 0000000000..c4336f3f32
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_active_configuration.js
@@ -0,0 +1,115 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async () => {
+  info(
+    "Checking that the profiler can fetch the information about the active " +
+      "configuration that is being used to power the profiler."
+  );
+
+  equal(
+    Services.profiler.activeConfiguration,
+    null,
+    "When the profile is off, there is no active configuration."
+  );
+
+  {
+    info("Start the profiler.");
+    const entries = 10000;
+    const interval = 1;
+    const threads = ["GeckoMain"];
+    const features = ["js"];
+    const activeTabID = 123;
+    await Services.profiler.StartProfiler(
+      entries,
+      interval,
+      features,
+      threads,
+      activeTabID
+    );
+
+    info("Generate the activeConfiguration.");
+    const { activeConfiguration } = Services.profiler;
+    const expectedConfiguration = {
+      interval,
+      threads,
+      features,
+      activeTabID,
+      // The buffer is created as a power of two that can fit all of the entires
+      // into it. If the ratio of entries to buffer size ever changes, this setting
+      // will need to be updated.
+      capacity: Math.pow(2, 14),
+    };
+
+    deepEqual(
+      activeConfiguration,
+      expectedConfiguration,
+      "The active configuration matches configuration given."
+    );
+
+    info("Get the profile.");
+    const profile = Services.profiler.getProfileData();
+    deepEqual(
+      profile.meta.configuration,
+      expectedConfiguration,
+      "The configuration also matches on the profile meta object."
+    );
+  }
+
+  {
+    const entries = 20000;
+    const interval = 0.5;
+    const threads = ["GeckoMain", "DOM Worker"];
+    const features = [];
+    const activeTabID = 111;
+    const duration = 20;
+
+    info("Restart the profiler with a new configuration.");
+    await Services.profiler.StartProfiler(
+      entries,
+      interval,
+      features,
+      threads,
+      activeTabID,
+      // Also start it with duration, this property is optional.
+      duration
+    );
+
+    info("Generate the activeConfiguration.");
+    const { activeConfiguration } = Services.profiler;
+    const expectedConfiguration = {
+      interval,
+      threads,
+      features,
+      activeTabID,
+      duration,
+      // The buffer is created as a power of two that can fit all of the entires
+      // into it. If the ratio of entries to buffer size ever changes, this setting
+      // will need to be updated.
+      capacity: Math.pow(2, 15),
+    };
+
+    deepEqual(
+      activeConfiguration,
+      expectedConfiguration,
+      "The active configuration matches the new configuration."
+    );
+
+    info("Get the profile.");
+    const profile = Services.profiler.getProfileData();
+    deepEqual(
+      profile.meta.configuration,
+      expectedConfiguration,
+      "The configuration also matches on the profile meta object."
+    );
+  }
+
+  await Services.profiler.StopProfiler();
+
+  equal(
+    Services.profiler.activeConfiguration,
+    null,
+    "When the profile is off, there is no active configuration."
+  );
+});
diff --git a/tools/profiler/tests/xpcshell/test_addProfilerMarker.js b/tools/profiler/tests/xpcshell/test_addProfilerMarker.js
new file mode 100644
index 0000000000..b11545a41c
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_addProfilerMarker.js
@@ -0,0 +1,221 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that ChromeUtils.addProfilerMarker is working correctly.
+ */
+
+const markerNamePrefix = "test_addProfilerMarker";
+const markerText = "Text payload";
+// The same startTime will be used for all markers with a duration,
+// and we store this value globally so that expectDuration and
+// expectNoDuration can access it. The value isn't set here as we
+// want a start time after the profiler has started
+var startTime;
+
+function expectNoDuration(marker) {
+  Assert.equal(
+    typeof marker.startTime,
+    "number",
+    "startTime should be a number"
+  );
+  Assert.greater(
+    marker.startTime,
+    startTime,
+    "startTime should be after the begining of the test"
+  );
+  Assert.equal(typeof marker.endTime, "number", "endTime should be a number");
+  Assert.equal(marker.endTime, 0, "endTime should be 0");
+}
+
+function expectDuration(marker) {
+  Assert.equal(
+    typeof marker.startTime,
+    "number",
+    "startTime should be a number"
+  );
+  // Floats can cause rounding issues. We've seen up to a 4.17e-5 difference in
+  // intermittent failures, so we are permissive and accept up to 5e-5.
+  Assert.less(
+    Math.abs(marker.startTime - startTime),
+    5e-5,
+    "startTime should be the expected time"
+  );
+  Assert.equal(typeof marker.endTime, "number", "endTime should be a number");
+  Assert.greater(
+    marker.endTime,
+    startTime,
+    "endTime should be after startTime"
+  );
+}
+
+function expectNoData(marker) {
+  Assert.equal(
+    typeof marker.data,
+    "undefined",
+    "The data property should be undefined"
+  );
+}
+
+function expectText(marker) {
+  Assert.equal(
+    typeof marker.data,
+    "object",
+    "The data property should be an object"
+  );
+  Assert.equal(marker.data.type, "Text", "Should be a Text marker");
+  Assert.equal(
+    marker.data.name,
+    markerText,
+    "The payload should contain the expected text"
+  );
+}
+
+function expectNoStack(marker) {
+  Assert.ok(!marker.data || !marker.data.stack, "There should be no stack");
+}
+
+function expectStack(marker, thread) {
+  let stack = marker.data.stack;
+  Assert.ok(!!stack, "There should be a stack");
+
+  // Marker stacks are recorded as a profile of a thread with a single sample,
+  // get the stack id.
+  stack = stack.samples.data[0][stack.samples.schema.stack];
+
+  const stackPrefixCol = thread.stackTable.schema.prefix;
+  const stackFrameCol = thread.stackTable.schema.frame;
+  const frameLocationCol = thread.frameTable.schema.location;
+
+  // Get the entire stack in an array for easier processing.
+  let result = [];
+  while (stack != null) {
+    let stackEntry = thread.stackTable.data[stack];
+    let frame = thread.frameTable.data[stackEntry[stackFrameCol]];
+    result.push(thread.stringTable[frame[frameLocationCol]]);
+    stack = stackEntry[stackPrefixCol];
+  }
+
+  Assert.greaterOrEqual(
+    result.length,
+    1,
+    "There should be at least one frame in the stack"
+  );
+
+  Assert.ok(
+    result.some(frame => frame.includes("testMarker")),
+    "the 'testMarker' function should be visible in the stack"
+  );
+
+  Assert.ok(
+    !result.some(frame => frame.includes("ChromeUtils.addProfilerMarker")),
+    "the 'ChromeUtils.addProfilerMarker' label frame should not be visible in the stack"
+  );
+}
+
+add_task(async () => {
+  startProfilerForMarkerTests();
+  startTime = Cu.now();
+  while (Cu.now() < startTime + 1) {
+    // Busy wait for 1ms to ensure the intentionally set start time of markers
+    // will be significantly different from the time at which the marker is
+    // recorded.
+  }
+  info("startTime used for markers with durations: " + startTime);
+
+  /* Each call to testMarker will record a marker with a unique name.
+   * The testFunctions and testCases objects contain respectively test
+   * functions to verify that the marker found in the captured profile
+   * matches expectations, and a string that can be printed to describe
+   * in which way ChromeUtils.addProfilerMarker was called. */
+  let testFunctions = {};
+  let testCases = {};
+  let markerId = 0;
+  function testMarker(args, checks) {
+    let name = markerNamePrefix + markerId++;
+    ChromeUtils.addProfilerMarker(name, ...args);
+    testFunctions[name] = checks;
+    testCases[name] = `ChromeUtils.addProfilerMarker(${[name, ...args]
+      .toSource()
+      .slice(1, -1)})`;
+  }
+
+  info("Record markers without options object.");
+  testMarker([], m => {
+    expectNoDuration(m);
+    expectNoData(m);
+  });
+  testMarker([startTime], m => {
+    expectDuration(m);
+    expectNoData(m);
+  });
+  testMarker([undefined, markerText], m => {
+    expectNoDuration(m);
+    expectText(m);
+  });
+  testMarker([startTime, markerText], m => {
+    expectDuration(m);
+    expectText(m);
+  });
+
+  info("Record markers providing the duration as the startTime property.");
+  testMarker([{ startTime }], m => {
+    expectDuration(m);
+    expectNoData(m);
+  });
+  testMarker([{}, markerText], m => {
+    expectNoDuration(m);
+    expectText(m);
+  });
+  testMarker([{ startTime }, markerText], m => {
+    expectDuration(m);
+    expectText(m);
+  });
+
+  info("Record markers to test the captureStack property.");
+  const captureStack = true;
+  testMarker([], expectNoStack);
+  testMarker([startTime, markerText], expectNoStack);
+  testMarker([{ captureStack: false }], expectNoStack);
+  testMarker([{ captureStack }], expectStack);
+  testMarker([{ startTime, captureStack }], expectStack);
+  testMarker([{ captureStack }, markerText], expectStack);
+  testMarker([{ startTime, captureStack }, markerText], expectStack);
+
+  info("Record markers to test the category property");
+  function testCategory(args, expectedCategory) {
+    testMarker(args, marker => {
+      Assert.equal(marker.category, expectedCategory);
+    });
+  }
+  testCategory([], "JavaScript");
+  testCategory([{ category: "Test" }], "Test");
+  testCategory([{ category: "Test" }, markerText], "Test");
+  testCategory([{ category: "JavaScript" }], "JavaScript");
+  testCategory([{ category: "Other" }], "Other");
+  testCategory([{ category: "DOM" }], "DOM");
+  testCategory([{ category: "does not exist" }], "Other");
+
+  info("Capture the profile");
+  const profile = await stopNowAndGetProfile();
+  const mainThread = profile.threads.find(({ name }) => name === "GeckoMain");
+  const markers = getInflatedMarkerData(mainThread).filter(m =>
+    m.name.startsWith(markerNamePrefix)
+  );
+  Assert.equal(
+    markers.length,
+    Object.keys(testFunctions).length,
+    `Found ${markers.length} test markers in the captured profile`
+  );
+
+  for (let marker of markers) {
+    marker.category = profile.meta.categories[marker.category].name;
+    info(`${testCases[marker.name]} -> ${marker.toSource()}`);
+
+    testFunctions[marker.name](marker, mainThread);
+    delete testFunctions[marker.name];
+  }
+
+  Assert.equal(0, Object.keys(testFunctions).length, "all markers were found");
+});
diff --git a/tools/profiler/tests/xpcshell/test_asm.js b/tools/profiler/tests/xpcshell/test_asm.js
new file mode 100644
index 0000000000..ced36ce429
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_asm.js
@@ -0,0 +1,76 @@
+// Check that asm.js code shows up on the stack.
+add_task(async () => {
+  // This test assumes that it's starting on an empty profiler stack.
+  // (Note that the other profiler tests also assume the profiler
+  // isn't already started.)
+  Assert.ok(!Services.profiler.IsActive());
+
+  let jsFuns = Cu.getJSTestingFunctions();
+  if (!jsFuns.isAsmJSCompilationAvailable()) {
+    return;
+  }
+
+  const ms = 10;
+  await Services.profiler.StartProfiler(10000, ms, ["js"]);
+
+  let stack = null;
+  function ffi_function() {
+    var delayMS = 5;
+    while (1) {
+      let then = Date.now();
+      do {
+        // do nothing
+      } while (Date.now() - then < delayMS);
+
+      var thread0 = Services.profiler.getProfileData().threads[0];
+
+      if (delayMS > 30000) {
+        return;
+      }
+
+      delayMS *= 2;
+
+      if (!thread0.samples.data.length) {
+        continue;
+      }
+
+      var lastSample = thread0.samples.data[thread0.samples.data.length - 1];
+      stack = String(getInflatedStackLocations(thread0, lastSample));
+      if (stack.includes("trampoline")) {
+        return;
+      }
+    }
+  }
+
+  function asmjs_module(global, ffis) {
+    "use asm";
+    var ffi = ffis.ffi;
+    function asmjs_function() {
+      ffi();
+    }
+    return asmjs_function;
+  }
+
+  Assert.ok(jsFuns.isAsmJSModule(asmjs_module));
+
+  var asmjs_function = asmjs_module(null, { ffi: ffi_function });
+  Assert.ok(jsFuns.isAsmJSFunction(asmjs_function));
+
+  asmjs_function();
+
+  Assert.notEqual(stack, null);
+
+  var i1 = stack.indexOf("entry trampoline");
+  Assert.ok(i1 !== -1);
+  var i2 = stack.indexOf("asmjs_function");
+  Assert.ok(i2 !== -1);
+  var i3 = stack.indexOf("exit trampoline");
+  Assert.ok(i3 !== -1);
+  var i4 = stack.indexOf("ffi_function");
+  Assert.ok(i4 !== -1);
+  Assert.ok(i1 < i2);
+  Assert.ok(i2 < i3);
+  Assert.ok(i3 < i4);
+
+  await Services.profiler.StopProfiler();
+});
diff --git a/tools/profiler/tests/xpcshell/test_assertion_helper.js b/tools/profiler/tests/xpcshell/test_assertion_helper.js
new file mode 100644
index 0000000000..baa4c34818
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_assertion_helper.js
@@ -0,0 +1,162 @@
+add_task(function setup() {
+  // With the default reporter, an assertion doesn't throw if it fails, it
+  // merely report the result to the reporter and then go on. But in this test
+  // we want that a failure really throws, so that we can actually assert that
+  // it throws in case of failures!
+  // That's why we disable the default repoter here.
+  // I noticed that this line needs to be in an add_task (or possibly run_test)
+  // function. If put outside this will crash the test.
+  Assert.setReporter(null);
+});
+
+add_task(function test_objectContains() {
+  const fixture = {
+    foo: "foo",
+    bar: "bar",
+  };
+
+  Assert.objectContains(fixture, { foo: "foo" }, "Matches one property value");
+  Assert.objectContains(
+    fixture,
+    { foo: "foo", bar: "bar" },
+    "Matches both properties"
+  );
+  Assert.objectContainsOnly(
+    fixture,
+    { foo: "foo", bar: "bar" },
+    "Matches both properties"
+  );
+  Assert.throws(
+    () => Assert.objectContainsOnly(fixture, { foo: "foo" }),
+    /AssertionError/,
+    "Fails if some properties are missing"
+  );
+  Assert.throws(
+    () => Assert.objectContains(fixture, { foo: "bar" }),
+    /AssertionError/,
+    "Fails if the value for a present property is wrong"
+  );
+  Assert.throws(
+    () => Assert.objectContains(fixture, { hello: "world" }),
+    /AssertionError/,
+    "Fails if an expected property is missing"
+  );
+  Assert.throws(
+    () => Assert.objectContains(fixture, { foo: "foo", hello: "world" }),
+    /AssertionError/,
+    "Fails if some properties are present but others are missing"
+  );
+});
+
+add_task(function test_objectContains_expectations() {
+  const fixture = {
+    foo: "foo",
+    bar: "bar",
+    num: 42,
+    nested: {
+      nestedFoo: "nestedFoo",
+      nestedBar: "nestedBar",
+    },
+  };
+
+  Assert.objectContains(
+    fixture,
+    {
+      foo: Expect.stringMatches(/^fo/),
+      bar: Expect.stringContains("ar"),
+      num: Expect.number(),
+      nested: Expect.objectContainsOnly({
+        nestedFoo: Expect.stringMatches(/[Ff]oo/),
+        nestedBar: Expect.stringMatches(/[Bb]ar/),
+      }),
+    },
+    "Supports expectations"
+  );
+  Assert.objectContainsOnly(
+    fixture,
+    {
+      foo: Expect.stringMatches(/^fo/),
+      bar: Expect.stringContains("ar"),
+      num: Expect.number(),
+      nested: Expect.objectContains({
+        nestedFoo: Expect.stringMatches(/[Ff]oo/),
+      }),
+    },
+    "Supports expectations"
+  );
+
+  Assert.objectContains(fixture, {
+    num: val => Assert.greater(val, 40),
+  });
+
+  // Failed expectations
+  Assert.throws(
+    () =>
+      Assert.objectContains(fixture, {
+        foo: Expect.stringMatches(/bar/),
+      }),
+    /AssertionError/,
+    "Expect.stringMatches shouldn't match when the value is unexpected"
+  );
+  Assert.throws(
+    () =>
+      Assert.objectContains(fixture, {
+        foo: Expect.stringContains("bar"),
+      }),
+    /AssertionError/,
+    "Expect.stringContains shouldn't match when the value is unexpected"
+  );
+  Assert.throws(
+    () =>
+      Assert.objectContains(fixture, {
+        foo: Expect.number(),
+      }),
+    /AssertionError/,
+    "Expect.number shouldn't match when the value isn't a number"
+  );
+  Assert.throws(
+    () =>
+      Assert.objectContains(fixture, {
+        nested: Expect.objectContains({
+          nestedFoo: "bar",
+        }),
+      }),
+    /AssertionError/,
+    "Expect.objectContains should throw when the value is unexpected"
+  );
+
+  Assert.throws(
+    () =>
+      Assert.objectContains(fixture, {
+        num: val => Assert.less(val, 40),
+      }),
+    /AssertionError/,
+    "Expect.objectContains should throw when a function assertion fails"
+  );
+});
+
+add_task(function test_type_expectations() {
+  const fixture = {
+    any: "foo",
+    string: "foo",
+    number: 42,
+    boolean: true,
+    bigint: 42n,
+    symbol: Symbol("foo"),
+    object: { foo: "foo" },
+    function1() {},
+    function2: () => {},
+  };
+
+  Assert.objectContains(fixture, {
+    any: Expect.any(),
+    string: Expect.string(),
+    number: Expect.number(),
+    boolean: Expect.boolean(),
+    bigint: Expect.bigint(),
+    symbol: Expect.symbol(),
+    object: Expect.object(),
+    function1: Expect.function(),
+    function2: Expect.function(),
+  });
+});
diff --git a/tools/profiler/tests/xpcshell/test_enterjit_osr.js b/tools/profiler/tests/xpcshell/test_enterjit_osr.js
new file mode 100644
index 0000000000..86845ddc76
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_enterjit_osr.js
@@ -0,0 +1,52 @@
+// Check that the EnterJIT frame, added by the JIT trampoline and
+// usable by a native unwinder to resume unwinding after encountering
+// JIT code, is pushed as expected.
+function run_test() {
+  // This test assumes that it's starting on an empty profiler stack.
+  // (Note that the other profiler tests also assume the profiler
+  // isn't already started.)
+  Assert.ok(!Services.profiler.IsActive());
+
+  const ms = 5;
+  Services.profiler.StartProfiler(10000, ms, ["js"]);
+
+  function has_arbitrary_name_in_stack() {
+    // A frame for |arbitrary_name| has been pushed.  Do a sequence of
+    // increasingly long spins until we get a sample.
+    var delayMS = 5;
+    while (1) {
+      info("loop: ms = " + delayMS);
+      const then = Date.now();
+      do {
+        let n = 10000;
+        // eslint-disable-next-line no-empty
+        while (--n) {} // OSR happens here
+        // Spin in the hope of getting a sample.
+      } while (Date.now() - then < delayMS);
+      let profile = Services.profiler.getProfileData().threads[0];
+
+      // Go through all of the stacks, and search for this function name.
+      for (const sample of profile.samples.data) {
+        const stack = getInflatedStackLocations(profile, sample);
+        info(`The following stack was found: ${stack}`);
+        for (var i = 0; i < stack.length; i++) {
+          if (stack[i].match(/arbitrary_name/)) {
+            // This JS sample was correctly found.
+            return true;
+          }
+        }
+      }
+
+      // Continue running this function with an increasingly long delay.
+      delayMS *= 2;
+      if (delayMS > 30000) {
+        return false;
+      }
+    }
+  }
+  Assert.ok(
+    has_arbitrary_name_in_stack(),
+    "A JS frame was found before the test timeout."
+  );
+  Services.profiler.StopProfiler();
+}
diff --git a/tools/profiler/tests/xpcshell/test_enterjit_osr_disabling.js b/tools/profiler/tests/xpcshell/test_enterjit_osr_disabling.js
new file mode 100644
index 0000000000..c5bc264623
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_enterjit_osr_disabling.js
@@ -0,0 +1,14 @@
+function run_test() {
+  Assert.ok(!Services.profiler.IsActive());
+
+  Services.profiler.StartProfiler(100, 10, ["js"]);
+  // The function is entered with the profiler enabled
+  (function() {
+    Services.profiler.StopProfiler();
+    let n = 10000;
+    // eslint-disable-next-line no-empty
+    while (--n) {} // OSR happens here with the profiler disabled.
+    // An assertion will fail when this function returns, if the
+    // profiler stack was misbalanced.
+  })();
+}
diff --git a/tools/profiler/tests/xpcshell/test_enterjit_osr_enabling.js b/tools/profiler/tests/xpcshell/test_enterjit_osr_enabling.js
new file mode 100644
index 0000000000..47f6259047
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_enterjit_osr_enabling.js
@@ -0,0 +1,14 @@
+function run_test() {
+  Assert.ok(!Services.profiler.IsActive());
+
+  // The function is entered with the profiler disabled.
+  (function() {
+    Services.profiler.StartProfiler(100, 10, ["js"]);
+    let n = 10000;
+    // eslint-disable-next-line no-empty
+    while (--n) {} // OSR happens here with the profiler enabled.
+    // An assertion will fail when this function returns, if the
+    // profiler stack was misbalanced.
+  })();
+  Services.profiler.StopProfiler();
+}
diff --git a/tools/profiler/tests/xpcshell/test_feature_fileioall.js b/tools/profiler/tests/xpcshell/test_feature_fileioall.js
new file mode 100644
index 0000000000..e5ac040b98
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_fileioall.js
@@ -0,0 +1,159 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async () => {
+  info(
+    "Test that off-main thread fileio is captured for a profiled thread, " +
+      "and that it will be sent to the main thread."
+  );
+  const filename = "test_marker_fileio";
+  const profile = await startProfilerAndTriggerFileIO({
+    features: ["fileioall"],
+    threadsFilter: ["GeckoMain", "BgIOThreadPool"],
+    filename,
+  });
+
+  const threads = getThreads(profile);
+  const mainThread = threads.find(thread => thread.name === "GeckoMain");
+  const mainThreadFileIO = getInflatedFileIOMarkers(mainThread, filename);
+  let backgroundThread;
+  let backgroundThreadFileIO;
+  for (const thread of threads) {
+    // Check for FileIO in any of the background threads.
+    if (thread.name.startsWith("BgIOThreadPool")) {
+      const markers = getInflatedFileIOMarkers(thread, filename);
+      if (markers.length) {
+        backgroundThread = thread;
+        backgroundThreadFileIO = markers;
+        break;
+      }
+    }
+  }
+
+  info("Check all of the main thread FileIO markers.");
+  checkInflatedFileIOMarkers(mainThreadFileIO, filename);
+  for (const { data, name } of mainThreadFileIO) {
+    equal(
+      name,
+      "FileIO (non-main thread)",
+      "The markers from off main thread are labeled as such."
+    );
+    equal(
+      data.threadId,
+      backgroundThread.tid,
+      "The main thread FileIO markers were all sent from the background thread."
+    );
+  }
+
+  info("Check all of the background thread FileIO markers.");
+  checkInflatedFileIOMarkers(backgroundThreadFileIO, filename);
+  for (const { data, name } of backgroundThreadFileIO) {
+    equal(
+      name,
+      "FileIO",
+      "The markers on the thread where they were generated just say FileIO"
+    );
+    equal(
+      data.threadId,
+      undefined,
+      "The background thread FileIO correctly excludes the threadId."
+    );
+  }
+});
+
+add_task(async () => {
+  info(
+    "Test that off-main thread fileio is captured for a thread that is not profiled, " +
+      "and that it will be sent to the main thread."
+  );
+  const filename = "test_marker_fileio";
+  const profile = await startProfilerAndTriggerFileIO({
+    features: ["fileioall"],
+    threadsFilter: ["GeckoMain"],
+    filename,
+  });
+
+  const threads = getThreads(profile);
+  const mainThread = threads.find(thread => thread.name === "GeckoMain");
+  const mainThreadFileIO = getInflatedFileIOMarkers(mainThread, filename);
+
+  info("Check all of the main thread FileIO markers.");
+  checkInflatedFileIOMarkers(mainThreadFileIO, filename);
+  for (const { data, name } of mainThreadFileIO) {
+    equal(
+      name,
+      "FileIO (non-profiled thread)",
+      "The markers from off main thread are labeled as such."
+    );
+    equal(typeof data.threadId, "number", "A thread ID is captured.");
+  }
+});
+
+/**
+ * @typedef {Object} TestConfig
+ * @prop {Array} features The list of profiler features
+ * @prop {string[]} threadsFilter The list of threads to profile
+ * @prop {string} filename A filename to trigger a write operation
+ */
+
+/**
+ * Start the profiler and get FileIO markers.
+ * @param {TestConfig}
+ * @returns {Profile}
+ */
+async function startProfilerAndTriggerFileIO({
+  features,
+  threadsFilter,
+  filename,
+}) {
+  const entries = 10000;
+  const interval = 10;
+  await Services.profiler.StartProfiler(
+    entries,
+    interval,
+    features,
+    threadsFilter
+  );
+
+  const path = PathUtils.join(PathUtils.tempDir, filename);
+
+  info(`Using a temporary file to test FileIO: ${path}`);
+
+  if (fileExists(path)) {
+    console.warn(
+      "This test is triggering FileIO by writing to a file. However, the test found an " +
+        "existing file at the location it was trying to write to. This could happen " +
+        "because a previous run of the test failed to clean up after itself. This test " +
+        " will now clean up that file before running the test again."
+    );
+    await removeFile(path);
+  }
+
+  info("Write to the file, but do so using a background thread.");
+
+  // IOUtils handles file operations using a background thread.
+  await IOUtils.write(path, new TextEncoder().encode("Test data."));
+  const exists = await fileExists(path);
+  ok(exists, `Created temporary file at: ${path}`);
+
+  info("Remove the file");
+  await removeFile(path);
+
+  return stopNowAndGetProfile();
+}
+
+async function fileExists(file) {
+  try {
+    let { type } = await IOUtils.stat(file);
+    return type === "regular";
+  } catch (_error) {
+    return false;
+  }
+}
+
+async function removeFile(file) {
+  await IOUtils.remove(file);
+  const exists = await fileExists(file);
+  ok(!exists, `Removed temporary file: ${file}`);
+}
diff --git a/tools/profiler/tests/xpcshell/test_feature_java.js b/tools/profiler/tests/xpcshell/test_feature_java.js
new file mode 100644
index 0000000000..e2f6879c2b
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_java.js
@@ -0,0 +1,31 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that Java capturing works as expected.
+ */
+add_task(async () => {
+  info("Test that Android Java sampler works as expected.");
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = ["java"];
+
+  Services.profiler.StartProfiler(entries, interval, features, threads);
+  Assert.ok(Services.profiler.IsActive());
+
+  await captureAtLeastOneJsSample();
+
+  info(
+    "Stop the profiler and check that we have successfully captured a profile" +
+      " with the AndroidUI thread."
+  );
+  const profile = await stopNowAndGetProfile();
+  Assert.notEqual(profile, null);
+  const androidUiThread = profile.threads.find(
+    thread => thread.name == "AndroidUI (JVM)"
+  );
+  Assert.notEqual(androidUiThread, null);
+  Assert.ok(!Services.profiler.IsActive());
+});
diff --git a/tools/profiler/tests/xpcshell/test_feature_js.js b/tools/profiler/tests/xpcshell/test_feature_js.js
new file mode 100644
index 0000000000..a5949e4a0c
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_js.js
@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that JS capturing works as expected.
+ */
+add_task(async () => {
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = ["js"];
+
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+
+  // Call the following to get a nice stack in the profiler:
+  // functionA -> functionB -> functionC -> captureAtLeastOneJsSample
+  const sampleIndex = await functionA();
+
+  const profile = await stopNowAndGetProfile();
+
+  const [thread] = profile.threads;
+  const { samples } = thread;
+
+  const inflatedStackFrames = getInflatedStackLocations(
+    thread,
+    samples.data[sampleIndex]
+  );
+
+  expectStackToContain(
+    inflatedStackFrames,
+    [
+      "(root)",
+      "js::RunScript",
+      // The following regexes match a string similar to:
+      //
+      // "functionA (/gecko/obj/_tests/xpcshell/tools/profiler/tests/xpcshell/test_feature_js.js:47:0)"
+      // or
+      // "functionA (test_feature_js.js:47:0)"
+      //
+      //          this matches the script location
+      //          |                       match the line number
+      //          |                       |   match the column number
+      //          v                       v   v
+      /^functionA \(.*test_feature_js\.js:\d+:\d+\)$/,
+      /^functionB \(.*test_feature_js\.js:\d+:\d+\)$/,
+      /^functionC \(.*test_feature_js\.js:\d+:\d+\)$/,
+    ],
+    "The stack contains a few frame labels, as well as the JS functions that we called."
+  );
+});
+
+function functionA() {
+  return functionB();
+}
+
+function functionB() {
+  return functionC();
+}
+
+async function functionC() {
+  return captureAtLeastOneJsSample();
+}
diff --git a/tools/profiler/tests/xpcshell/test_feature_mainthreadio.js b/tools/profiler/tests/xpcshell/test_feature_mainthreadio.js
new file mode 100644
index 0000000000..8ff5c9206d
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_mainthreadio.js
@@ -0,0 +1,122 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const { FileUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/FileUtils.sys.mjs"
+);
+
+/**
+ * Test that the IOInterposer is working correctly to capture main thread IO.
+ *
+ * This test should not run on release or beta, as the IOInterposer is wrapped in
+ * an ifdef.
+ */
+add_task(async () => {
+  {
+    const filename = "profiler-mainthreadio-test-firstrun";
+    const { markers, schema } = await runProfilerWithFileIO(
+      ["mainthreadio"],
+      filename
+    );
+    info("Check the FileIO markers when using the mainthreadio feature");
+    checkInflatedFileIOMarkers(markers, filename);
+
+    checkSchema(schema, {
+      name: "FileIO",
+      display: ["marker-chart", "marker-table", "timeline-fileio"],
+      data: [
+        {
+          key: "operation",
+          label: "Operation",
+          format: "string",
+          searchable: true,
+        },
+        { key: "source", label: "Source", format: "string", searchable: true },
+        {
+          key: "filename",
+          label: "Filename",
+          format: "file-path",
+          searchable: true,
+        },
+        {
+          key: "threadId",
+          label: "Thread ID",
+          format: "string",
+          searchable: true,
+        },
+      ],
+    });
+  }
+
+  {
+    const filename = "profiler-mainthreadio-test-no-instrumentation";
+    const { markers } = await runProfilerWithFileIO([], filename);
+    equal(
+      markers.length,
+      0,
+      "No FileIO markers are found when the mainthreadio feature is not turned on " +
+        "in the profiler."
+    );
+  }
+
+  {
+    const filename = "profiler-mainthreadio-test-secondrun";
+    const { markers } = await runProfilerWithFileIO(["mainthreadio"], filename);
+    info("Check the FileIO markers when re-starting the mainthreadio feature");
+    checkInflatedFileIOMarkers(markers, filename);
+  }
+});
+
+/**
+ * Start the profiler and get FileIO markers and schema.
+ *
+ * @param {Array} features The list of profiler features
+ * @param {string} filename A filename to trigger a write operation
+ * @returns {{
+ *   markers: InflatedMarkers[];
+ *   schema: MarkerSchema;
+ * }}
+ */
+async function runProfilerWithFileIO(features, filename) {
+  const entries = 10000;
+  const interval = 10;
+  const threads = [];
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+
+  info("Get the file");
+  const file = FileUtils.getFile("TmpD", [filename]);
+  if (file.exists()) {
+    console.warn(
+      "This test is triggering FileIO by writing to a file. However, the test found an " +
+        "existing file at the location it was trying to write to. This could happen " +
+        "because a previous run of the test failed to clean up after itself. This test " +
+        " will now clean up that file before running the test again."
+    );
+    file.remove(false);
+  }
+
+  info(
+    "Generate file IO on the main thread using FileUtils.openSafeFileOutputStream."
+  );
+  const outputStream = FileUtils.openSafeFileOutputStream(file);
+
+  const data = "Test data.";
+  info("Write to the file");
+  outputStream.write(data, data.length);
+
+  info("Close the file");
+  FileUtils.closeSafeFileOutputStream(outputStream);
+
+  info("Remove the file");
+  file.remove(false);
+
+  const profile = await stopNowAndGetProfile();
+  const mainThread = profile.threads.find(({ name }) => name === "GeckoMain");
+
+  const schema = getSchema(profile, "FileIO");
+
+  const markers = getInflatedFileIOMarkers(mainThread, filename);
+
+  return { schema, markers };
+}
diff --git a/tools/profiler/tests/xpcshell/test_feature_nativeallocations.js b/tools/profiler/tests/xpcshell/test_feature_nativeallocations.js
new file mode 100644
index 0000000000..64398d7ef9
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_nativeallocations.js
@@ -0,0 +1,158 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async () => {
+  if (!Services.profiler.GetFeatures().includes("nativeallocations")) {
+    Assert.ok(
+      true,
+      "Native allocations are not supported by this build, " +
+        "skip run the rest of the test."
+    );
+    return;
+  }
+
+  Assert.ok(
+    !Services.profiler.IsActive(),
+    "The profiler is not currently active"
+  );
+
+  info(
+    "Test that the profiler can install memory hooks and collect native allocation " +
+      "information in the marker payloads."
+  );
+  {
+    info("Start the profiler.");
+    await startProfiler({
+      // Only instrument the main thread.
+      threads: ["GeckoMain"],
+      features: ["js", "nativeallocations"],
+    });
+
+    info(
+      "Do some JS work for a little bit. This will increase the amount of allocations " +
+        "that take place."
+    );
+    doWork();
+
+    info("Get the profile data and analyze it.");
+    const profile = await waitSamplingAndStopAndGetProfile();
+
+    const {
+      allocationPayloads,
+      unmatchedAllocations,
+      logAllocationsAndDeallocations,
+    } = getAllocationInformation(profile);
+
+    Assert.greater(
+      allocationPayloads.length,
+      0,
+      "Native allocation payloads were recorded for the parent process' main thread when " +
+        "the Native Allocation feature was turned on."
+    );
+
+    if (unmatchedAllocations.length !== 0) {
+      info(
+        "There were unmatched allocations. Log all of the allocations and " +
+          "deallocations in order to aid debugging."
+      );
+      logAllocationsAndDeallocations();
+      ok(
+        false,
+        "Found a deallocation that did not have a matching allocation site. " +
+          "This could happen if balanced allocations is broken, or if the the " +
+          "buffer size of this test was too small, and some markers ended up " +
+          "rolling off."
+      );
+    }
+
+    ok(true, "All deallocation sites had matching allocations.");
+  }
+
+  info("Restart the profiler, to ensure that we get no more allocations.");
+  {
+    await startProfiler({ features: ["js"] });
+    info("Do some work again.");
+    doWork();
+    info("Wait for the periodic sampling.");
+    const profile = await waitSamplingAndStopAndGetProfile();
+    const allocationPayloads = getPayloadsOfType(
+      profile.threads[0],
+      "Native allocation"
+    );
+
+    Assert.equal(
+      allocationPayloads.length,
+      0,
+      "No native allocations were collected when the feature was disabled."
+    );
+  }
+});
+
+function doWork() {
+  this.n = 0;
+  for (let i = 0; i < 1e5; i++) {
+    this.n += Math.random();
+  }
+}
+
+/**
+ * Extract the allocation payloads, and find the unmatched allocations.
+ */
+function getAllocationInformation(profile) {
+  // Get all of the allocation payloads.
+  const allocationPayloads = getPayloadsOfType(
+    profile.threads[0],
+    "Native allocation"
+  );
+
+  // Decide what is an allocation and deallocation.
+  const allocations = allocationPayloads.filter(
+    payload => ensureIsNumber(payload.size) >= 0
+  );
+  const deallocations = allocationPayloads.filter(
+    payload => ensureIsNumber(payload.size) < 0
+  );
+
+  // Now determine the unmatched allocations by building a set
+  const allocationSites = new Set(
+    allocations.map(({ memoryAddress }) => memoryAddress)
+  );
+
+  const unmatchedAllocations = deallocations.filter(
+    ({ memoryAddress }) => !allocationSites.has(memoryAddress)
+  );
+
+  // Provide a helper to log out the allocations and deallocations on failure.
+  function logAllocationsAndDeallocations() {
+    for (const { memoryAddress } of allocations) {
+      console.log("Allocations", formatHex(memoryAddress));
+      allocationSites.add(memoryAddress);
+    }
+
+    for (const { memoryAddress } of deallocations) {
+      console.log("Deallocations", formatHex(memoryAddress));
+    }
+
+    for (const { memoryAddress } of unmatchedAllocations) {
+      console.log("Deallocation with no allocation", formatHex(memoryAddress));
+    }
+  }
+
+  return {
+    allocationPayloads,
+    unmatchedAllocations,
+    logAllocationsAndDeallocations,
+  };
+}
+
+function ensureIsNumber(value) {
+  if (typeof value !== "number") {
+    throw new Error(`Expected a number: ${value}`);
+  }
+  return value;
+}
+
+function formatHex(number) {
+  return `0x${number.toString(16)}`;
+}
diff --git a/tools/profiler/tests/xpcshell/test_feature_stackwalking.js b/tools/profiler/tests/xpcshell/test_feature_stackwalking.js
new file mode 100644
index 0000000000..aa0bc86547
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_feature_stackwalking.js
@@ -0,0 +1,48 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Do a basic test to see if native frames are being collected for stackwalking. This
+ * test is fairly naive, as it does not attempt to check that these are valid symbols,
+ * only that some kind of stack walking is happening. It does this by making sure at
+ * least two native frames are collected.
+ */
+add_task(async () => {
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = ["stackwalk"];
+
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+  const sampleIndex = await captureAtLeastOneJsSample();
+
+  const profile = await stopNowAndGetProfile();
+  const [thread] = profile.threads;
+  const { samples } = thread;
+
+  const inflatedStackFrames = getInflatedStackLocations(
+    thread,
+    samples.data[sampleIndex]
+  );
+  const nativeStack = /^0x[0-9a-f]+$/;
+
+  expectStackToContain(
+    inflatedStackFrames,
+    [
+      "(root)",
+      // There are probably more native stacks here.
+      nativeStack,
+      nativeStack,
+      // Since this is an xpcshell test we know that JavaScript will run:
+      "js::RunScript",
+      // There are probably more native stacks here.
+      nativeStack,
+      nativeStack,
+    ],
+    "Expected native stacks to be interleaved between some frame labels. There should" +
+      "be more than one native stack if stack walking is working correctly. There " +
+      "is no attempt here to determine if the memory addresses point to the correct " +
+      "symbols"
+  );
+});
diff --git a/tools/profiler/tests/xpcshell/test_get_features.js b/tools/profiler/tests/xpcshell/test_get_features.js
new file mode 100644
index 0000000000..e9bf0047c8
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_get_features.js
@@ -0,0 +1,8 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function run_test() {
+  var profilerFeatures = Services.profiler.GetFeatures();
+  Assert.ok(profilerFeatures != null);
+}
diff --git a/tools/profiler/tests/xpcshell/test_merged_stacks.js b/tools/profiler/tests/xpcshell/test_merged_stacks.js
new file mode 100644
index 0000000000..7f851e8de9
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_merged_stacks.js
@@ -0,0 +1,74 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we correctly merge the three stack types, JS, native, and frame labels.
+ */
+add_task(async () => {
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = ["js", "stackwalk"];
+
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+
+  // Call the following to get a nice stack in the profiler:
+  // functionA -> functionB -> functionC
+  const sampleIndex = await functionA();
+
+  const profile = await stopNowAndGetProfile();
+  const [thread] = profile.threads;
+  const { samples } = thread;
+
+  const inflatedStackFrames = getInflatedStackLocations(
+    thread,
+    samples.data[sampleIndex]
+  );
+
+  const nativeStack = /^0x[0-9a-f]+$/;
+
+  expectStackToContain(
+    inflatedStackFrames,
+    [
+      "(root)",
+      nativeStack,
+      nativeStack,
+      // There are more native stacks and frame labels here, but we know some execute
+      // and then the "js::RunScript" frame label runs.
+      "js::RunScript",
+      nativeStack,
+      nativeStack,
+      // The following regexes match a string similar to:
+      //
+      // "functionA (/gecko/obj/_tests/xpcshell/tools/profiler/tests/xpcshell/test_merged_stacks.js:47:0)"
+      // or
+      // "functionA (test_merged_stacks.js:47:0)"
+      //
+      //          this matches the script location
+      //          |                          match the line number
+      //          |                          |   match the column number
+      //          v                          v   v
+      /^functionA \(.*test_merged_stacks\.js:\d+:\d+\)$/,
+      /^functionB \(.*test_merged_stacks\.js:\d+:\d+\)$/,
+      /^functionC \(.*test_merged_stacks\.js:\d+:\d+\)$/,
+      // After the JS frames, then there are a bunch of arbitrary native stack frames
+      // that run.
+      nativeStack,
+      nativeStack,
+    ],
+    "The stack contains a few frame labels, as well as the JS functions that we called."
+  );
+});
+
+async function functionA() {
+  return functionB();
+}
+
+async function functionB() {
+  return functionC();
+}
+
+async function functionC() {
+  return captureAtLeastOneJsSample();
+}
diff --git a/tools/profiler/tests/xpcshell/test_pause.js b/tools/profiler/tests/xpcshell/test_pause.js
new file mode 100644
index 0000000000..0e621fb19f
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_pause.js
@@ -0,0 +1,126 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async () => {
+  Assert.ok(!Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+
+  let startPromise = Services.profiler.StartProfiler(1000, 10, []);
+
+  // Default: Active and not paused.
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  await startPromise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  // Pause everything, implicitly pauses sampling.
+  let pausePromise = Services.profiler.Pause();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await pausePromise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  // While fully paused, pause and resume sampling only, no expected changes.
+  let pauseSamplingPromise = Services.profiler.PauseSampling();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await pauseSamplingPromise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  let resumeSamplingPromise = Services.profiler.ResumeSampling();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await resumeSamplingPromise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  // Resume everything.
+  let resumePromise = Services.profiler.Resume();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  await resumePromise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  // Pause sampling only.
+  let pauseSampling2Promise = Services.profiler.PauseSampling();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await pauseSampling2Promise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  // While sampling is paused, pause everything.
+  let pause2Promise = Services.profiler.Pause();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await pause2Promise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  // Resume, but sampling is still paused separately.
+  let resume2promise = Services.profiler.Resume();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  await resume2promise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(Services.profiler.IsSamplingPaused());
+
+  // Resume sampling only.
+  let resumeSampling2Promise = Services.profiler.ResumeSampling();
+
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  await resumeSampling2Promise;
+  Assert.ok(Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  let stopPromise = Services.profiler.StopProfiler();
+  Assert.ok(!Services.profiler.IsActive());
+  // Stopping is not pausing.
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+
+  await stopPromise;
+  Assert.ok(!Services.profiler.IsActive());
+  Assert.ok(!Services.profiler.IsPaused());
+  Assert.ok(!Services.profiler.IsSamplingPaused());
+});
diff --git a/tools/profiler/tests/xpcshell/test_responsiveness.js b/tools/profiler/tests/xpcshell/test_responsiveness.js
new file mode 100644
index 0000000000..5f57173090
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_responsiveness.js
@@ -0,0 +1,50 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Test that we can measure non-zero event delays
+ */
+
+add_task(async () => {
+  const entries = 10000;
+  const interval = 1;
+  const threads = [];
+  const features = [];
+
+  await Services.profiler.StartProfiler(entries, interval, features, threads);
+
+  await functionA();
+
+  const profile = await stopNowAndGetProfile();
+  const [thread] = profile.threads;
+  const { samples } = thread;
+  const message = "eventDelay > 0 not found.";
+  let SAMPLE_STACK_SLOT = thread.samples.schema.eventDelay;
+
+  for (let i = 0; i < samples.data.length; i++) {
+    if (samples.data[i][SAMPLE_STACK_SLOT] > 0) {
+      Assert.ok(true, message);
+      return;
+    }
+  }
+  Assert.ok(false, message);
+});
+
+function doSyncWork(milliseconds) {
+  const start = Date.now();
+  while (true) {
+    this.n = 0;
+    for (let i = 0; i < 1e5; i++) {
+      this.n += Math.random();
+    }
+    if (Date.now() - start > milliseconds) {
+      return;
+    }
+  }
+}
+
+async function functionA() {
+  doSyncWork(100);
+  return captureAtLeastOneJsSample();
+}
diff --git a/tools/profiler/tests/xpcshell/test_run.js b/tools/profiler/tests/xpcshell/test_run.js
new file mode 100644
index 0000000000..0e30edfd4e
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_run.js
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function run_test() {
+  Assert.ok(!Services.profiler.IsActive());
+
+  Services.profiler.StartProfiler(1000, 10, []);
+
+  Assert.ok(Services.profiler.IsActive());
+
+  do_test_pending();
+
+  do_timeout(1000, function wait() {
+    // Check text profile format
+    var profileStr = Services.profiler.GetProfile();
+    Assert.ok(profileStr.length > 10);
+
+    // check json profile format
+    var profileObj = Services.profiler.getProfileData();
+    Assert.notEqual(profileObj, null);
+    Assert.notEqual(profileObj.threads, null);
+    // We capture memory counters by default only when jemalloc is turned
+    // on (and it isn't for ASAN), so unless we can conditionalize for ASAN
+    // here we can't check that we're capturing memory counter data.
+    Assert.notEqual(profileObj.counters, null);
+    Assert.notEqual(profileObj.memory, null);
+    Assert.ok(profileObj.threads.length >= 1);
+    Assert.notEqual(profileObj.threads[0].samples, null);
+    // NOTE: The number of samples will be empty since we
+    //       don't have any labels in the xpcshell code
+
+    Services.profiler.StopProfiler();
+    Assert.ok(!Services.profiler.IsActive());
+    do_test_finished();
+  });
+}
diff --git a/tools/profiler/tests/xpcshell/test_shared_library.js b/tools/profiler/tests/xpcshell/test_shared_library.js
new file mode 100644
index 0000000000..e211ca642b
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_shared_library.js
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+function run_test() {
+  var libs = Services.profiler.sharedLibraries;
+
+  Assert.equal(typeof libs, "object");
+  Assert.ok(Array.isArray(libs));
+  Assert.equal(typeof libs, "object");
+  Assert.ok(libs.length >= 1);
+  Assert.equal(typeof libs[0], "object");
+  Assert.equal(typeof libs[0].name, "string");
+  Assert.equal(typeof libs[0].path, "string");
+  Assert.equal(typeof libs[0].debugName, "string");
+  Assert.equal(typeof libs[0].debugPath, "string");
+  Assert.equal(typeof libs[0].arch, "string");
+  Assert.equal(typeof libs[0].start, "number");
+  Assert.equal(typeof libs[0].end, "number");
+  Assert.ok(libs[0].start <= libs[0].end);
+}
diff --git a/tools/profiler/tests/xpcshell/test_start.js b/tools/profiler/tests/xpcshell/test_start.js
new file mode 100644
index 0000000000..c9ae135eb8
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/test_start.js
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+add_task(async () => {
+  Assert.ok(!Services.profiler.IsActive());
+
+  let startPromise = Services.profiler.StartProfiler(10, 100, []);
+
+  Assert.ok(Services.profiler.IsActive());
+
+  await startPromise;
+  Assert.ok(Services.profiler.IsActive());
+
+  let stopPromise = Services.profiler.StopProfiler();
+
+  Assert.ok(!Services.profiler.IsActive());
+
+  await stopPromise;
+  Assert.ok(!Services.profiler.IsActive());
+});
diff --git a/tools/profiler/tests/xpcshell/xpcshell.ini b/tools/profiler/tests/xpcshell/xpcshell.ini
new file mode 100644
index 0000000000..a7c461b4ac
--- /dev/null
+++ b/tools/profiler/tests/xpcshell/xpcshell.ini
@@ -0,0 +1,72 @@
+[DEFAULT]
+head = head.js
+support-files =
+  ../shared-head.js
+
+[test_active_configuration.js]
+skip-if = tsan # Intermittent timeouts, bug 1781449
+[test_addProfilerMarker.js]
+[test_start.js]
+skip-if = true
+[test_get_features.js]
+[test_responsiveness.js]
+skip-if = tsan # Times out on TSan, bug 1612707
+[test_shared_library.js]
+[test_run.js]
+skip-if = true
+[test_pause.js]
+[test_enterjit_osr.js]
+[test_enterjit_osr_disabling.js]
+skip-if = !debug
+[test_enterjit_osr_enabling.js]
+skip-if = !debug
+[test_asm.js]
+[test_feature_mainthreadio.js]
+skip-if =
+  release_or_beta
+  os == "win" && socketprocess_networking
+[test_feature_fileioall.js]
+skip-if =
+  release_or_beta
+
+# The sanitizer checks appears to overwrite our own memory hooks in xpcshell tests,
+# and no allocation markers are gathered. Skip this test in that configuration.
+[test_feature_nativeallocations.js]
+skip-if =
+  os == "android" && verify # bug 1757528
+  asan
+  tsan
+  socketprocess_networking
+
+# Native stackwalking is somewhat unreliable depending on the platform.
+#
+# We don't have frame pointers on macOS release and beta, so stack walking does not
+# work. See Bug 1571216 for more details.
+#
+# Linux can be very unreliable when native stackwalking through JavaScript code.
+# See Bug 1434402 for more details.
+#
+# For sanitizer builds, there were many intermittents, and we're not getting much
+# additional coverage there, so it's better to be a bit more reliable.
+[test_feature_stackwalking.js]
+skip-if =
+  os == "mac" && release_or_beta
+  os == "linux" && release_or_beta && !debug
+  asan
+  tsan
+
+[test_feature_js.js]
+skip-if = tsan # Times out on TSan, bug 1612707
+
+# See the comment on test_feature_stackwalking.js
+[test_merged_stacks.js]
+skip-if =
+  os == "mac" && release_or_beta
+  os == "linux" && release_or_beta && !debug
+  asan
+  tsan
+
+[test_assertion_helper.js]
+[test_feature_java.js]
+skip-if =
+  os != "android"