Adding upstream version 86.0.1.upstream/86.0.1upstream

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

72 files changed, 5774 insertions, 0 deletions

diff --git a/toolkit/content/tests/browser/audio.ogg b/toolkit/content/tests/browser/audio.ogg
new file mode 100644
index 0000000000..7f1833508a
--- /dev/null
+++ b/toolkit/content/tests/browser/audio.ogg
diff --git a/toolkit/content/tests/browser/browser.ini b/toolkit/content/tests/browser/browser.ini
new file mode 100644
index 0000000000..927178c3a9
--- /dev/null
+++ b/toolkit/content/tests/browser/browser.ini
@@ -0,0 +1,118 @@
+[DEFAULT]
+prefs =
+  plugin.load_flash_only=false
+  media.cubeb.sandbox=false # BMO 1610640
+support-files =
+  audio.ogg
+  empty.png
+  file_contentTitle.html
+  file_empty.html
+  file_findinframe.html
+  file_mediaPlayback2.html
+  file_multipleAudio.html
+  file_multiplePlayingAudio.html
+  file_nonAutoplayAudio.html
+  file_redirect.html
+  file_redirect_to.html
+  file_silentAudioTrack.html
+  file_webAudio.html
+  head.js
+  image.jpg
+  image_page.html
+  silentAudioTrack.webm
+
+[browser_autoscroll_disabled.js]
+skip-if = true # Bug 1312652
+[browser_delay_autoplay_media.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_media_pausedAfterPlay.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_playAfterTabVisible.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_multipleMedia.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_notInTreeAudio.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_playMediaInMuteTab.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_delay_autoplay_silentAudioTrack_media.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") || (os == "mac") || (os == "linux" && !debug) # aarch64 due to 1536573 #Bug 1524746
+[browser_delay_autoplay_webAudio.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_bug1572798.js]
+tags = audiochannel
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+support-files = file_document_open_audio.html
+[browser_bug1170531.js]
+skip-if =
+    os == "linux" && !debug && !ccov # Bug 1647973
+[browser_bug1198465.js]
+[browser_bug295977_autoscroll_overflow.js]
+skip-if = ((debug || asan) && os == "win" && bits == 64)
+[browser_bug451286.js]
+skip-if = true # bug 1399845 tracks re-enabling this test.
+[browser_bug594509.js]
+[browser_bug982298.js]
+[browser_charsetMenu_swapBrowsers.js]
+[browser_content_url_annotation.js]
+skip-if = !e10s || !crashreporter
+[browser_contentTitle.js]
+[browser_crash_previous_frameloader.js]
+run-if = e10s && crashreporter
+[browser_datetime_datepicker.js]
+skip-if = tsan # Frequently times out on TSan
+[browser_default_image_filename.js]
+[browser_default_image_filename_redirect.js]
+support-files =
+  doggy.png
+  firebird.png
+  firebird.png^headers^
+[browser_f7_caret_browsing.js]
+[browser_findbar.js]
+skip-if = os == "linux" && bits == 64 && os_version = "18.04" # Bug 1614739
+[browser_findbar_disabled_manual.js]
+[browser_isSynthetic.js]
+[browser_keyevents_during_autoscrolling.js]
+[browser_label_textlink.js]
+[browser_remoteness_change_listeners.js]
+[browser_suspend_videos_outside_viewport.js]
+support-files =
+  file_outside_viewport_videos.html
+  gizmo.mp4
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_license_links.js]
+[browser_media_wakelock.js]
+support-files =
+  browser_mediaStreamPlayback.html
+  browser_mediaStreamPlaybackWithoutAudio.html
+  file_video.html
+  file_videoWithAudioOnly.html
+  file_videoWithoutAudioTrack.html
+  gizmo.mp4
+  gizmo-noaudio.webm
+skip-if = (os == "win" && processor == "aarch64") # aarch64 due to 1536573
+[browser_media_wakelock_PIP.js]
+support-files =
+  file_video.html
+  gizmo.mp4
+[browser_media_wakelock_webaudio.js]
+[browser_quickfind_editable.js]
+skip-if = (verify && debug && (os == 'linux'))
+[browser_save_resend_postdata.js]
+support-files =
+  common/mockTransfer.js
+  data/post_form_inner.sjs
+  data/post_form_outer.sjs
+skip-if = e10s # Bug ?????? - test directly manipulates content (gBrowser.contentDocument.getElementById("postForm").submit();)
+[browser_saveImageURL.js]
+[browser_resume_bkg_video_on_tab_hover.js]
+skip-if = (os == "win" && processor == "aarch64") || debug # aarch64 due to 1536573, Bug 1388959
+
diff --git a/toolkit/content/tests/browser/browser_autoscroll_disabled.js b/toolkit/content/tests/browser/browser_autoscroll_disabled.js
new file mode 100644
index 0000000000..d2f6efbd13
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_autoscroll_disabled.js
@@ -0,0 +1,82 @@
+add_task(async function() {
+  const kPrefName_AutoScroll = "general.autoScroll";
+  Services.prefs.setBoolPref(kPrefName_AutoScroll, false);
+
+  let dataUri =
+    'data:text/html,<html><body id="i" style="overflow-y: scroll"><div style="height: 2000px"></div>\
+      <iframe id="iframe" style="display: none;"></iframe>\
+</body></html>';
+
+  let loadedPromise = BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
+  BrowserTestUtils.loadURI(gBrowser, dataUri);
+  await loadedPromise;
+
+  await BrowserTestUtils.synthesizeMouse(
+    "#i",
+    50,
+    50,
+    { button: 1 },
+    gBrowser.selectedBrowser
+  );
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], async function() {
+    var iframe = content.document.getElementById("iframe");
+
+    if (iframe) {
+      var e = new iframe.contentWindow.PageTransitionEvent("pagehide", {
+        bubbles: true,
+        cancelable: true,
+        persisted: false,
+      });
+      iframe.contentDocument.dispatchEvent(e);
+      iframe.contentDocument.documentElement.dispatchEvent(e);
+    }
+  });
+
+  await BrowserTestUtils.synthesizeMouse(
+    "#i",
+    100,
+    100,
+    { type: "mousemove", clickCount: "0" },
+    gBrowser.selectedBrowser
+  );
+
+  // If scrolling didn't work, we wouldn't do any redraws and thus time out, so
+  // request and force redraws to get the chance to check for scrolling at all.
+  await new Promise(resolve => window.requestAnimationFrame(resolve));
+
+  let msg = await SpecialPowers.spawn(
+    gBrowser.selectedBrowser,
+    [],
+    async function() {
+      // Skip the first animation frame callback as it's the same callback that
+      // the browser uses to kick off the scrolling.
+      return new Promise(resolve => {
+        function checkScroll() {
+          let msg = "";
+          let elem = content.document.getElementById("i");
+          if (elem.scrollTop != 0) {
+            msg += "element should not have scrolled vertically";
+          }
+          if (elem.scrollLeft != 0) {
+            msg += "element should not have scrolled horizontally";
+          }
+
+          resolve(msg);
+        }
+
+        content.requestAnimationFrame(checkScroll);
+      });
+    }
+  );
+
+  ok(!msg, "element scroll " + msg);
+
+  // restore the changed prefs
+  if (Services.prefs.prefHasUserValue(kPrefName_AutoScroll)) {
+    Services.prefs.clearUserPref(kPrefName_AutoScroll);
+  }
+
+  // wait for focus to fix a failure in the next test if the latter runs too soon.
+  await SimpleTest.promiseFocus();
+});
diff --git a/toolkit/content/tests/browser/browser_bug1170531.js b/toolkit/content/tests/browser/browser_bug1170531.js
new file mode 100644
index 0000000000..d5a6501dcd
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug1170531.js
@@ -0,0 +1,112 @@
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+// Test for bug 1170531
+// https://bugzilla.mozilla.org/show_bug.cgi?id=1170531
+
+add_task(async function() {
+  // Get a bunch of DOM nodes
+  let editMenu = document.getElementById("edit-menu");
+  let menuPopup = editMenu.menupopup;
+
+  let closeMenu = function(aCallback) {
+    if (OS.Constants.Sys.Name == "Darwin") {
+      executeSoon(aCallback);
+      return;
+    }
+
+    menuPopup.addEventListener(
+      "popuphidden",
+      function() {
+        executeSoon(aCallback);
+      },
+      { once: true }
+    );
+
+    executeSoon(function() {
+      editMenu.open = false;
+    });
+  };
+
+  let openMenu = function(aCallback) {
+    if (OS.Constants.Sys.Name == "Darwin") {
+      goUpdateGlobalEditMenuItems();
+      // On OSX, we have a native menu, so it has to be updated. In single process browsers,
+      // this happens synchronously, but in e10s, we have to wait for the main thread
+      // to deal with it for us. 1 second should be plenty of time.
+      setTimeout(aCallback, 1000);
+      return;
+    }
+
+    menuPopup.addEventListener(
+      "popupshown",
+      function() {
+        executeSoon(aCallback);
+      },
+      { once: true }
+    );
+
+    executeSoon(function() {
+      editMenu.open = true;
+    });
+  };
+
+  await BrowserTestUtils.withNewTab(
+    { gBrowser, url: "about:blank" },
+    async function(browser) {
+      let menu_cut_disabled, menu_copy_disabled;
+
+      BrowserTestUtils.loadURI(browser, "data:text/html,<div>hello!</div>");
+      await BrowserTestUtils.browserLoaded(browser);
+      browser.focus();
+      await new Promise(resolve => waitForFocus(resolve, window));
+      await new Promise(resolve =>
+        window.requestAnimationFrame(() => executeSoon(resolve))
+      );
+      await new Promise(openMenu);
+      menu_cut_disabled =
+        menuPopup.querySelector("#menu_cut").getAttribute("disabled") == "true";
+      is(menu_cut_disabled, false, "menu_cut should be enabled");
+      menu_copy_disabled =
+        menuPopup.querySelector("#menu_copy").getAttribute("disabled") ==
+        "true";
+      is(menu_copy_disabled, false, "menu_copy should be enabled");
+      await new Promise(closeMenu);
+
+      BrowserTestUtils.loadURI(
+        browser,
+        "data:text/html,<div contentEditable='true'>hello!</div>"
+      );
+      await BrowserTestUtils.browserLoaded(browser);
+      browser.focus();
+      await new Promise(resolve => waitForFocus(resolve, window));
+      await new Promise(resolve =>
+        window.requestAnimationFrame(() => executeSoon(resolve))
+      );
+      await new Promise(openMenu);
+      menu_cut_disabled =
+        menuPopup.querySelector("#menu_cut").getAttribute("disabled") == "true";
+      is(menu_cut_disabled, false, "menu_cut should be enabled");
+      menu_copy_disabled =
+        menuPopup.querySelector("#menu_copy").getAttribute("disabled") ==
+        "true";
+      is(menu_copy_disabled, false, "menu_copy should be enabled");
+      await new Promise(closeMenu);
+
+      BrowserTestUtils.loadURI(browser, "about:preferences");
+      await BrowserTestUtils.browserLoaded(browser);
+      browser.focus();
+      await new Promise(resolve => waitForFocus(resolve, window));
+      await new Promise(resolve =>
+        window.requestAnimationFrame(() => executeSoon(resolve))
+      );
+      await new Promise(openMenu);
+      menu_cut_disabled =
+        menuPopup.querySelector("#menu_cut").getAttribute("disabled") == "true";
+      is(menu_cut_disabled, true, "menu_cut should be disabled");
+      menu_copy_disabled =
+        menuPopup.querySelector("#menu_copy").getAttribute("disabled") ==
+        "true";
+      is(menu_copy_disabled, true, "menu_copy should be disabled");
+      await new Promise(closeMenu);
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_bug1198465.js b/toolkit/content/tests/browser/browser_bug1198465.js
new file mode 100644
index 0000000000..7f578b3197
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug1198465.js
@@ -0,0 +1,76 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+var kPrefName = "accessibility.typeaheadfind.prefillwithselection";
+var kEmptyURI = "data:text/html,";
+
+// This pref is false by default in OSX; ensure the test still works there.
+Services.prefs.setBoolPref(kPrefName, true);
+
+registerCleanupFunction(function() {
+  Services.prefs.clearUserPref(kPrefName);
+});
+
+add_task(async function() {
+  let aTab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kEmptyURI);
+  ok(!gFindBarInitialized, "findbar isn't initialized yet");
+
+  // Note: the use case here is when the user types directly in the findbar
+  // _before_ it's prefilled with a text selection in the page.
+
+  // So `yield BrowserTestUtils.sendChar()` can't be used here:
+  //  - synthesizing a key in the browser won't actually send it to the
+  //    findbar; the findbar isn't part of the browser content.
+  //  - we need to _not_ wait for _startFindDeferred to be resolved; yielding
+  //    a synthesized keypress on the browser implicitely happens after the
+  //    browser has dispatched its return message with the prefill value for
+  //    the findbar, which essentially nulls these tests.
+
+  // The parent-side of the sidebar initialization is also async, so we do
+  // need to wait for that. We verify a bit further down that _startFindDeferred
+  // hasn't been resolved yet.
+  await gFindBarPromise;
+
+  let findBar = gFindBar;
+  is(findBar._findField.value, "", "findbar is empty");
+
+  // Test 1
+  //  Any input in the findbar should erase a previous search.
+
+  findBar._findField.value = "xy";
+  findBar.startFind();
+  is(findBar._findField.value, "xy", "findbar should have xy initial query");
+  is(findBar._findField, document.activeElement, "findbar is now focused");
+
+  EventUtils.sendChar("z", window);
+  is(findBar._findField.value, "z", "z erases xy");
+
+  findBar._findField.value = "";
+  ok(!findBar._findField.value, "erase findbar after first test");
+
+  // Test 2
+  //  Prefilling the findbar should be ignored if a search has been run.
+
+  findBar.startFind();
+  ok(findBar._startFindDeferred, "prefilled value hasn't been fetched yet");
+  is(findBar._findField, document.activeElement, "findbar is still focused");
+
+  EventUtils.sendChar("a", window);
+  EventUtils.sendChar("b", window);
+  is(findBar._findField.value, "ab", "initial ab typed in the findbar");
+
+  // This resolves _startFindDeferred if it's still pending; let's just skip
+  // over waiting for the browser's return message that should do this as it
+  // doesn't really matter.
+  findBar.onCurrentSelection("foo", true);
+  ok(!findBar._startFindDeferred, "prefilled value fetched");
+  is(findBar._findField.value, "ab", "ab kept instead of prefill value");
+
+  EventUtils.sendChar("c", window);
+  is(findBar._findField.value, "abc", "c is appended after ab");
+
+  // Clear the findField value to make the test  run successfully
+  // for multiple runs in the same browser session.
+  findBar._findField.value = "";
+  BrowserTestUtils.removeTab(aTab);
+});
diff --git a/toolkit/content/tests/browser/browser_bug1572798.js b/toolkit/content/tests/browser/browser_bug1572798.js
new file mode 100644
index 0000000000..8b5dffd432
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug1572798.js
@@ -0,0 +1,29 @@
+add_task(async function test_bug_1572798() {
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  BrowserTestUtils.loadURI(
+    tab.linkedBrowser,
+    "https://example.com/browser/toolkit/content/tests/browser/file_document_open_audio.html"
+  );
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  let windowLoaded = BrowserTestUtils.waitForNewWindow();
+  info("- clicking button to spawn a new window -");
+  await ContentTask.spawn(tab.linkedBrowser, null, function() {
+    content.document.querySelector("button").click();
+  });
+  info("- waiting for the new window -");
+  let newWin = await windowLoaded;
+  info("- checking that the new window plays the audio -");
+  let documentOpenedBrowser = newWin.gBrowser.selectedBrowser;
+  await ContentTask.spawn(documentOpenedBrowser, null, async function() {
+    try {
+      await content.document.querySelector("audio").play();
+      ok(true, "Could play the audio");
+    } catch (e) {
+      ok(false, "Rejected audio promise" + e);
+    }
+  });
+
+  info("- Cleaning up -");
+  await BrowserTestUtils.closeWindow(newWin);
+  await BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_bug295977_autoscroll_overflow.js b/toolkit/content/tests/browser/browser_bug295977_autoscroll_overflow.js
new file mode 100644
index 0000000000..5cc6de19da
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug295977_autoscroll_overflow.js
@@ -0,0 +1,381 @@
+requestLongerTimeout(2);
+add_task(async function() {
+  function pushPrefs(prefs) {
+    return SpecialPowers.pushPrefEnv({ set: prefs });
+  }
+
+  await pushPrefs([
+    ["general.autoScroll", true],
+    ["test.events.async.enabled", true],
+  ]);
+
+  const expectScrollNone = 0;
+  const expectScrollVert = 1;
+  const expectScrollHori = 2;
+  const expectScrollBoth = 3;
+
+  var allTests = [
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><body><style type="text/css">div { display: inline-block; }</style>\
+      <div id="a" style="width: 100px; height: 100px; overflow: hidden;"><div style="width: 200px; height: 200px;"></div></div>\
+      <div id="b" style="width: 100px; height: 100px; overflow: auto;"><div style="width: 200px; height: 200px;"></div></div>\
+      <div id="c" style="width: 100px; height: 100px; overflow-x: auto; overflow-y: hidden;"><div style="width: 200px; height: 200px;"></div></div>\
+      <div id="d" style="width: 100px; height: 100px; overflow-y: auto; overflow-x: hidden;"><div style="width: 200px; height: 200px;"></div></div>\
+      <select id="e" style="width: 100px; height: 100px;" multiple="multiple"><option>aaaaaaaaaaaaaaaaaaaaaaaa</option><option>a</option><option>a</option>\
+      <option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option>\
+      <option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option></select>\
+      <select id="f" style="width: 100px; height: 100px;"><option>a</option><option>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</option><option>a</option>\
+      <option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option>\
+      <option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option><option>a</option></select>\
+      <div id="g" style="width: 99px; height: 99px; border: 10px solid black; margin: 10px; overflow: auto;"><div style="width: 100px; height: 100px;"></div></div>\
+      <div id="h" style="width: 100px; height: 100px; overflow: clip;"><div style="width: 200px; height: 200px;"></div></div>\
+      <iframe id="iframe" style="display: none;"></iframe>\
+      </body></html>',
+    },
+    { elem: "a", expected: expectScrollNone },
+    { elem: "b", expected: expectScrollBoth },
+    { elem: "c", expected: expectScrollHori },
+    { elem: "d", expected: expectScrollVert },
+    { elem: "e", expected: expectScrollVert },
+    { elem: "f", expected: expectScrollNone },
+    { elem: "g", expected: expectScrollBoth },
+    { elem: "h", expected: expectScrollNone },
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><body id="i" style="overflow-y: scroll"><div style="height: 2000px"></div>\
+      <iframe id="iframe" style="display: none;"></iframe>\
+      </body></html>',
+    },
+    { elem: "i", expected: expectScrollVert }, // bug 695121
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><style>html, body { width: 100%; height: 100%; overflow-x: hidden; overflow-y: scroll; }</style>\
+      <body id="j"><div style="height: 2000px"></div>\
+      <iframe id="iframe" style="display: none;"></iframe>\
+      </body></html>',
+    },
+    { elem: "j", expected: expectScrollVert }, // bug 914251
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8">\
+<style>\
+body > div {scroll-behavior: smooth;width: 300px;height: 300px;overflow: scroll;}\
+body > div > div {width: 1000px;height: 1000px;}\
+</style>\
+</head><body><div id="t"><div></div></div></body></html>',
+    },
+    { elem: "t", expected: expectScrollBoth }, // bug 1308775
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><body>\
+<div id="k" style="height: 150px;  width: 200px; overflow: scroll; border: 1px solid black;">\
+<iframe style="height: 200px; width: 300px;"></iframe>\
+</div>\
+<div id="l" style="height: 150px;  width: 300px; overflow: scroll; border: 1px dashed black;">\
+<iframe style="height: 200px; width: 200px;" src="data:text/html,<div style=\'border: 5px solid blue; height: 200%; width: 200%;\'></div>"></iframe>\
+</div>\
+<iframe id="m"></iframe>\
+<div style="height: 200%; border: 5px dashed black;">filler to make document overflow: scroll;</div>\
+</body></html>',
+    },
+    { elem: "k", expected: expectScrollBoth },
+    { elem: "k", expected: expectScrollNone, testwindow: true },
+    { elem: "l", expected: expectScrollNone },
+    { elem: "m", expected: expectScrollVert, testwindow: true },
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><body>\
+<img width="100" height="100" alt="image map" usemap="%23planetmap">\
+<map name="planetmap">\
+  <area id="n" shape="rect" coords="0,0,100,100" href="javascript:void(null)">\
+</map>\
+<a href="javascript:void(null)" id="o" style="width: 100px; height: 100px; border: 1px solid black; display: inline-block; vertical-align: top;">link</a>\
+<input id="p" style="width: 100px; height: 100px; vertical-align: top;">\
+<textarea id="q" style="width: 100px; height: 100px; vertical-align: top;"></textarea>\
+<div style="height: 200%; border: 1px solid black;"></div>\
+</body></html>',
+    },
+    { elem: "n", expected: expectScrollNone, testwindow: true },
+    { elem: "o", expected: expectScrollNone, testwindow: true },
+    {
+      elem: "p",
+      expected: expectScrollVert,
+      testwindow: true,
+      middlemousepastepref: false,
+    },
+    {
+      elem: "q",
+      expected: expectScrollVert,
+      testwindow: true,
+      middlemousepastepref: false,
+    },
+    {
+      dataUri:
+        'data:text/html,<html><head><meta charset="utf-8"></head><body>\
+<input id="r" style="width: 100px; height: 100px; vertical-align: top;">\
+<textarea id="s" style="width: 100px; height: 100px; vertical-align: top;"></textarea>\
+<div style="height: 200%; border: 1px solid black;"></div>\
+</body></html>',
+    },
+    {
+      elem: "r",
+      expected: expectScrollNone,
+      testwindow: true,
+      middlemousepastepref: true,
+    },
+    {
+      elem: "s",
+      expected: expectScrollNone,
+      testwindow: true,
+      middlemousepastepref: true,
+    },
+    {
+      dataUri:
+        "data:text/html," +
+        encodeURIComponent(`
+<!doctype html>
+<iframe id=i height=100 width=100 scrolling="no" srcdoc="<div style='height: 200px'>Auto-scrolling should never make me disappear"></iframe>
+<div style="height: 100vh"></div>
+      `),
+    },
+    {
+      elem: "i",
+      // We expect the outer window to scroll vertically, not the iframe's window.
+      expected: expectScrollVert,
+      testwindow: true,
+    },
+    {
+      dataUri:
+        "data:text/html," +
+        encodeURIComponent(`
+<!doctype html>
+<iframe id=i height=100 width=100 srcdoc="<div style='height: 200px'>Auto-scrolling should make me disappear"></iframe>
+<div style="height: 100vh"></div>
+      `),
+    },
+    {
+      elem: "i",
+      // We expect the iframe's window to scroll vertically, so the outer window should not scroll.
+      expected: expectScrollNone,
+      testwindow: true,
+    },
+    {
+      // Test: scroll is initiated in out of process iframe having no scrollable area
+      dataUri:
+        "data:text/html," +
+        encodeURIComponent(`
+<!doctype html>
+<head><meta content="text/html;charset=utf-8"></head><body>
+<div id="scroller" style="width: 300px; height: 300px; overflow-y: scroll; overflow-x: hidden; border: solid 1px blue;">
+  <iframe id="noscroll-outofprocess-iframe"
+          src="https://example.com/document-builder.sjs?html=<html><body>Hey!</body></html>"
+          style="border: solid 1px green; margin: 2px;"></iframe>
+  <div style="width: 100%; height: 200px;"></div>
+</div></body>
+        `),
+    },
+    {
+      elem: "noscroll-outofprocess-iframe",
+      // We expect the div to scroll vertically, not the iframe's window.
+      expected: expectScrollVert,
+      scrollable: "scroller",
+    },
+  ];
+
+  for (let test of allTests) {
+    if (test.dataUri) {
+      let loadedPromise = BrowserTestUtils.browserLoaded(
+        gBrowser.selectedBrowser
+      );
+      BrowserTestUtils.loadURI(gBrowser, test.dataUri);
+      await loadedPromise;
+      continue;
+    }
+
+    let prefsChanged = "middlemousepastepref" in test;
+    if (prefsChanged) {
+      await pushPrefs([["middlemouse.paste", test.middlemousepastepref]]);
+    }
+
+    await BrowserTestUtils.synthesizeMouse(
+      "#" + test.elem,
+      50,
+      80,
+      { button: 1 },
+      gBrowser.selectedBrowser
+    );
+
+    // This ensures bug 605127 is fixed: pagehide in an unrelated document
+    // should not cancel the autoscroll.
+    await ContentTask.spawn(
+      gBrowser.selectedBrowser,
+      { waitForAutoScrollStart: test.expected != expectScrollNone },
+      async ({ waitForAutoScrollStart }) => {
+        var iframe = content.document.getElementById("iframe");
+
+        if (iframe) {
+          var e = new iframe.contentWindow.PageTransitionEvent("pagehide", {
+            bubbles: true,
+            cancelable: true,
+            persisted: false,
+          });
+          iframe.contentDocument.dispatchEvent(e);
+          iframe.contentDocument.documentElement.dispatchEvent(e);
+        }
+        if (waitForAutoScrollStart) {
+          await new Promise(resolve =>
+            Services.obs.addObserver(resolve, "autoscroll-start")
+          );
+        }
+      }
+    );
+
+    is(
+      document.activeElement,
+      gBrowser.selectedBrowser,
+      "Browser still focused after autoscroll started"
+    );
+
+    await BrowserTestUtils.synthesizeMouse(
+      "#" + test.elem,
+      100,
+      100,
+      { type: "mousemove", clickCount: "0" },
+      gBrowser.selectedBrowser
+    );
+
+    if (prefsChanged) {
+      await SpecialPowers.popPrefEnv();
+    }
+
+    // Start checking for the scroll.
+    let firstTimestamp = undefined;
+    let timeCompensation;
+    do {
+      let timestamp = await new Promise(resolve =>
+        window.requestAnimationFrame(resolve)
+      );
+      if (firstTimestamp === undefined) {
+        firstTimestamp = timestamp;
+      }
+
+      // This value is calculated similarly to the value of the same name in
+      // ClickEventHandler.autoscrollLoop, except here it's cumulative across
+      // all frames after the first one instead of being based only on the
+      // current frame.
+      timeCompensation = (timestamp - firstTimestamp) / 20;
+      info(
+        "timestamp=" +
+          timestamp +
+          " firstTimestamp=" +
+          firstTimestamp +
+          " timeCompensation=" +
+          timeCompensation
+      );
+
+      // Try to wait until enough time has passed to allow the scroll to happen.
+      // autoscrollLoop incrementally scrolls during each animation frame, but
+      // due to how its calculations work, when a frame is very close to the
+      // previous frame, no scrolling may actually occur during that frame.
+      // After 100ms's worth of frames, timeCompensation will be 1, making it
+      // more likely that the accumulated scroll in autoscrollLoop will be >= 1,
+      // although it also depends on acceleration, which here in this test
+      // should be > 1 due to how it synthesizes mouse events below.
+    } while (timeCompensation < 5);
+
+    // Close the autoscroll popup by synthesizing Esc.
+    EventUtils.synthesizeKey("KEY_Escape");
+    let scrollVert = test.expected & expectScrollVert;
+    let scrollHori = test.expected & expectScrollHori;
+
+    await SpecialPowers.spawn(
+      gBrowser.selectedBrowser,
+      [
+        {
+          scrollVert,
+          scrollHori,
+          elemid: test.scrollable || test.elem,
+          checkWindow: test.testwindow,
+        },
+      ],
+      async function(args) {
+        let msg = "";
+        if (args.checkWindow) {
+          if (
+            !(
+              (args.scrollVert && content.scrollY > 0) ||
+              (!args.scrollVert && content.scrollY == 0)
+            )
+          ) {
+            msg += "Failed: ";
+          }
+          msg +=
+            "Window for " +
+            args.elemid +
+            " should" +
+            (args.scrollVert ? "" : " not") +
+            " have scrolled vertically\n";
+
+          if (
+            !(
+              (args.scrollHori && content.scrollX > 0) ||
+              (!args.scrollHori && content.scrollX == 0)
+            )
+          ) {
+            msg += "Failed: ";
+          }
+          msg +=
+            " Window for " +
+            args.elemid +
+            " should" +
+            (args.scrollHori ? "" : " not") +
+            " have scrolled horizontally\n";
+        } else {
+          let elem = content.document.getElementById(args.elemid);
+          if (
+            !(
+              (args.scrollVert && elem.scrollTop > 0) ||
+              (!args.scrollVert && elem.scrollTop == 0)
+            )
+          ) {
+            msg += "Failed: ";
+          }
+          msg +=
+            " " +
+            args.elemid +
+            " should" +
+            (args.scrollVert ? "" : " not") +
+            " have scrolled vertically\n";
+          if (
+            !(
+              (args.scrollHori && elem.scrollLeft > 0) ||
+              (!args.scrollHori && elem.scrollLeft == 0)
+            )
+          ) {
+            msg += "Failed: ";
+          }
+          msg +=
+            args.elemid +
+            " should" +
+            (args.scrollHori ? "" : " not") +
+            " have scrolled horizontally";
+        }
+
+        Assert.ok(!msg.includes("Failed"), msg);
+      }
+    );
+
+    // Before continuing the test, we need to ensure that the IPC
+    // message that stops autoscrolling has had time to arrive.
+    await new Promise(resolve => executeSoon(resolve));
+  }
+
+  // remove 2 tabs that were opened by middle-click on links
+  while (gBrowser.visibleTabs.length > 1) {
+    gBrowser.removeTab(gBrowser.visibleTabs[gBrowser.visibleTabs.length - 1]);
+  }
+
+  // wait for focus to fix a failure in the next test if the latter runs too soon.
+  await SimpleTest.promiseFocus();
+});
diff --git a/toolkit/content/tests/browser/browser_bug451286.js b/toolkit/content/tests/browser/browser_bug451286.js
new file mode 100644
index 0000000000..7856356608
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug451286.js
@@ -0,0 +1,166 @@
+Services.scriptloader.loadSubScript(
+  "chrome://mochikit/content/tests/SimpleTest/WindowSnapshot.js",
+  this
+);
+
+add_task(async function() {
+  const SEARCH_TEXT = "text";
+  const DATAURI = "data:text/html," + SEARCH_TEXT;
+
+  // Bug 451286. An iframe that should be highlighted
+  let visible = "<iframe id='visible' src='" + DATAURI + "'></iframe>";
+
+  // Bug 493658. An invisible iframe that shouldn't interfere with
+  // highlighting matches lying after it in the document
+  let invisible =
+    "<iframe id='invisible' style='display: none;' " +
+    "src='" +
+    DATAURI +
+    "'></iframe>";
+
+  let uri = DATAURI + invisible + SEARCH_TEXT + visible + SEARCH_TEXT;
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, uri);
+  let contentRect = tab.linkedBrowser.getBoundingClientRect();
+  let noHighlightSnapshot = snapshotRect(window, contentRect);
+  ok(noHighlightSnapshot, "Got noHighlightSnapshot");
+
+  await openFindBarAndWait();
+  gFindBar._findField.value = SEARCH_TEXT;
+  await findAgainAndWait();
+  var matchCase = gFindBar.getElement("find-case-sensitive");
+  if (matchCase.checked) {
+    matchCase.doCommand();
+  }
+
+  // Turn on highlighting
+  await toggleHighlightAndWait(true);
+  await closeFindBarAndWait();
+
+  // Take snapshot of highlighting
+  let findSnapshot = snapshotRect(window, contentRect);
+  ok(findSnapshot, "Got findSnapshot");
+
+  // Now, remove the highlighting, and take a snapshot to compare
+  // to our original state
+  await openFindBarAndWait();
+  await toggleHighlightAndWait(false);
+  await closeFindBarAndWait();
+
+  let unhighlightSnapshot = snapshotRect(window, contentRect);
+  ok(unhighlightSnapshot, "Got unhighlightSnapshot");
+
+  // Select the matches that should have been highlighted manually
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function() {
+    let doc = content.document;
+    let win = doc.defaultView;
+
+    // Create a manual highlight in the visible iframe to test bug 451286
+    let iframe = doc.getElementById("visible");
+    let ifBody = iframe.contentDocument.body;
+    let range = iframe.contentDocument.createRange();
+    range.selectNodeContents(ifBody.childNodes[0]);
+    let ifWindow = iframe.contentWindow;
+    let ifDocShell = ifWindow.docShell;
+
+    let ifController = ifDocShell
+      .QueryInterface(Ci.nsIInterfaceRequestor)
+      .getInterface(Ci.nsISelectionDisplay)
+      .QueryInterface(Ci.nsISelectionController);
+
+    let frameFindSelection = ifController.getSelection(
+      ifController.SELECTION_FIND
+    );
+    frameFindSelection.addRange(range);
+
+    // Create manual highlights in the main document (the matches that lie
+    // before/after the iframes
+    let docShell = win.docShell;
+
+    let controller = docShell
+      .QueryInterface(Ci.nsIInterfaceRequestor)
+      .getInterface(Ci.nsISelectionDisplay)
+      .QueryInterface(Ci.nsISelectionController);
+
+    let docFindSelection = controller.getSelection(ifController.SELECTION_FIND);
+
+    range = doc.createRange();
+    range.selectNodeContents(doc.body.childNodes[0]);
+    docFindSelection.addRange(range);
+    range = doc.createRange();
+    range.selectNodeContents(doc.body.childNodes[2]);
+    docFindSelection.addRange(range);
+    range = doc.createRange();
+    range.selectNodeContents(doc.body.childNodes[4]);
+    docFindSelection.addRange(range);
+  });
+
+  // Take snapshot of manual highlighting
+  let manualSnapshot = snapshotRect(window, contentRect);
+  ok(manualSnapshot, "Got manualSnapshot");
+
+  // Test 1: Were the matches in iframe correctly highlighted?
+  let res = compareSnapshots(findSnapshot, manualSnapshot, true);
+  ok(res[0], "Matches found in iframe correctly highlighted");
+
+  // Test 2: Were the matches in iframe correctly unhighlighted?
+  res = compareSnapshots(noHighlightSnapshot, unhighlightSnapshot, true);
+  ok(res[0], "Highlighting in iframe correctly removed");
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+function toggleHighlightAndWait(shouldHighlight) {
+  return new Promise(resolve => {
+    let listener = {
+      onFindResult() {},
+      onHighlightFinished() {
+        gFindBar.browser.finder.removeResultListener(listener);
+        resolve();
+      },
+      onMatchesCountResult() {},
+    };
+    gFindBar.browser.finder.addResultListener(listener);
+    gFindBar.toggleHighlight(shouldHighlight);
+  });
+}
+
+function findAgainAndWait() {
+  return new Promise(resolve => {
+    let listener = {
+      onFindResult() {
+        gFindBar.browser.finder.removeResultListener(listener);
+        resolve();
+      },
+      onHighlightFinished() {},
+      onMatchesCountResult() {},
+    };
+    gFindBar.browser.finder.addResultListener(listener);
+    gFindBar.onFindAgainCommand();
+  });
+}
+
+async function openFindBarAndWait() {
+  await gFindBarPromise;
+  let awaitTransitionEnd = BrowserTestUtils.waitForEvent(
+    gFindBar,
+    "transitionend"
+  );
+  gFindBar.open();
+  await awaitTransitionEnd;
+}
+
+// This test is comparing snapshots. It is necessary to wait for the gFindBar
+// to close before taking the snapshot so the gFindBar does not take up space
+// on the new snapshot.
+async function closeFindBarAndWait() {
+  let awaitTransitionEnd = BrowserTestUtils.waitForEvent(
+    gFindBar,
+    "transitionend",
+    false,
+    event => {
+      return event.propertyName == "visibility";
+    }
+  );
+  gFindBar.close();
+  await awaitTransitionEnd;
+}
diff --git a/toolkit/content/tests/browser/browser_bug594509.js b/toolkit/content/tests/browser/browser_bug594509.js
new file mode 100644
index 0000000000..cf93d2c71c
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug594509.js
@@ -0,0 +1,15 @@
+add_task(async function() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "about:rights"
+  );
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function() {
+    Assert.ok(
+      content.document.getElementById("your-rights"),
+      "about:rights content loaded"
+    );
+  });
+
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_bug982298.js b/toolkit/content/tests/browser/browser_bug982298.js
new file mode 100644
index 0000000000..99a4dc5e96
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_bug982298.js
@@ -0,0 +1,72 @@
+const scrollHtml =
+  '<textarea id="textarea1" row=2>Firefox\n\nFirefox\n\n\n\n\n\n\n\n\n\n' +
+  '</textarea><a href="about:blank">blank</a>';
+
+add_task(async function() {
+  let url = "data:text/html;base64," + btoa(scrollHtml);
+  await BrowserTestUtils.withNewTab({ gBrowser, url }, async function(browser) {
+    let awaitFindResult = new Promise(resolve => {
+      let listener = {
+        onFindResult(aData) {
+          info("got find result");
+          browser.finder.removeResultListener(listener);
+
+          ok(
+            aData.result == Ci.nsITypeAheadFind.FIND_FOUND,
+            "should find string"
+          );
+          resolve();
+        },
+        onCurrentSelection() {},
+        onMatchesCountResult() {},
+      };
+      info("about to add results listener, open find bar, and send 'F' string");
+      browser.finder.addResultListener(listener);
+    });
+    await gFindBarPromise;
+    gFindBar.onFindCommand();
+    EventUtils.sendString("F");
+    info("added result listener and sent string 'F'");
+    await awaitFindResult;
+
+    // scroll textarea to bottom
+    await SpecialPowers.spawn(browser, [], () => {
+      let textarea = content.document.getElementById("textarea1");
+      textarea.scrollTop = textarea.scrollHeight;
+    });
+    BrowserTestUtils.loadURI(browser, "about:blank");
+    await BrowserTestUtils.browserLoaded(browser);
+
+    ok(
+      browser.currentURI.spec == "about:blank",
+      "got load event for about:blank"
+    );
+
+    let awaitFindResult2 = new Promise(resolve => {
+      let listener = {
+        onFindResult(aData) {
+          info("got find result #2");
+          browser.finder.removeResultListener(listener);
+          resolve();
+        },
+        onCurrentSelection() {},
+        onMatchesCountResult() {},
+      };
+
+      browser.finder.addResultListener(listener);
+      info("added result listener");
+    });
+    // find again needs delay for crash test
+    setTimeout(function() {
+      // ignore exception if occured
+      try {
+        info("about to send find again command");
+        gFindBar.onFindAgainCommand(false);
+        info("sent find again command");
+      } catch (e) {
+        info("got exception from onFindAgainCommand: " + e);
+      }
+    }, 0);
+    await awaitFindResult2;
+  });
+});
diff --git a/toolkit/content/tests/browser/browser_charsetMenu_swapBrowsers.js b/toolkit/content/tests/browser/browser_charsetMenu_swapBrowsers.js
new file mode 100644
index 0000000000..8eda01de8e
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_charsetMenu_swapBrowsers.js
@@ -0,0 +1,34 @@
+/* Test that the charset menu is properly enabled when swapping browsers. */
+add_task(async function test() {
+  // NB: This test cheats and calls updateCharacterEncodingMenuState directly
+  // instead of opening the "View" menu.
+  function charsetMenuEnabled() {
+    updateCharacterEncodingMenuState();
+    return !document.getElementById("charsetMenu").hasAttribute("disabled");
+  }
+
+  const PAGE = "data:text/html,<!DOCTYPE html><body>hello";
+  let tab1 = await BrowserTestUtils.openNewForegroundTab({
+    gBrowser,
+    url: PAGE,
+  });
+  ok(charsetMenuEnabled(), "should have a charset menu here");
+
+  let tab2 = await BrowserTestUtils.openNewForegroundTab({ gBrowser });
+  ok(!charsetMenuEnabled(), "about:blank shouldn't have a charset menu");
+
+  await BrowserTestUtils.switchTab(gBrowser, tab1);
+
+  let swapped = BrowserTestUtils.waitForEvent(
+    tab2.linkedBrowser,
+    "SwapDocShells"
+  );
+
+  // NB: Closes tab1.
+  gBrowser.swapBrowsersAndCloseOther(tab2, tab1);
+  await swapped;
+
+  ok(charsetMenuEnabled(), "should have a charset after the swap");
+
+  BrowserTestUtils.removeTab(tab2);
+});
diff --git a/toolkit/content/tests/browser/browser_contentTitle.js b/toolkit/content/tests/browser/browser_contentTitle.js
new file mode 100644
index 0000000000..abd70809fc
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_contentTitle.js
@@ -0,0 +1,17 @@
+var url =
+  "https://example.com/browser/toolkit/content/tests/browser/file_contentTitle.html";
+
+add_task(async function() {
+  let tab = (gBrowser.selectedTab = BrowserTestUtils.addTab(gBrowser, url));
+  await BrowserTestUtils.waitForContentEvent(
+    tab.linkedBrowser,
+    "TestLocationChange",
+    true,
+    null,
+    true
+  );
+
+  is(gBrowser.contentTitle, "Test Page", "Should have the right title.");
+
+  gBrowser.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_content_url_annotation.js b/toolkit/content/tests/browser/browser_content_url_annotation.js
new file mode 100644
index 0000000000..72180ec2d0
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_content_url_annotation.js
@@ -0,0 +1,78 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+/* global Services, requestLongerTimeout, TestUtils, BrowserTestUtils,
+ ok, info, dump, is, Ci, Cu, Components, ctypes,
+ gBrowser, add_task, addEventListener, removeEventListener, ContentTask */
+
+"use strict";
+
+// Running this test in ASAN is slow.
+requestLongerTimeout(2);
+
+/**
+ * Removes a file from a directory. This is a no-op if the file does not
+ * exist.
+ *
+ * @param directory
+ *        The nsIFile representing the directory to remove from.
+ * @param filename
+ *        A string for the file to remove from the directory.
+ */
+function removeFile(directory, filename) {
+  let file = directory.clone();
+  file.append(filename);
+  if (file.exists()) {
+    file.remove(false);
+  }
+}
+
+/**
+ * Returns the directory where crash dumps are stored.
+ *
+ * @return nsIFile
+ */
+function getMinidumpDirectory() {
+  let dir = Services.dirsvc.get("ProfD", Ci.nsIFile);
+  dir.append("minidumps");
+  return dir;
+}
+
+/**
+ * Checks that the URL is correctly annotated on a content process crash.
+ */
+add_task(async function test_content_url_annotation() {
+  let url =
+    "https://example.com/browser/toolkit/content/tests/browser/file_redirect.html";
+  let redirect_url =
+    "https://example.com/browser/toolkit/content/tests/browser/file_redirect_to.html";
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+    },
+    async function(browser) {
+      ok(browser.isRemoteBrowser, "Should be a remote browser");
+
+      // file_redirect.html should send us to file_redirect_to.html
+      let promise = BrowserTestUtils.waitForContentEvent(
+        browser,
+        "RedirectDone",
+        true,
+        null,
+        true
+      );
+      BrowserTestUtils.loadURI(browser, url);
+      await promise;
+
+      // Crash the tab
+      let annotations = await BrowserTestUtils.crashFrame(browser);
+
+      ok("URL" in annotations, "annotated a URL");
+      is(
+        annotations.URL,
+        redirect_url,
+        "Should have annotated the URL after redirect"
+      );
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_crash_previous_frameloader.js b/toolkit/content/tests/browser/browser_crash_previous_frameloader.js
new file mode 100644
index 0000000000..6870cd825d
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_crash_previous_frameloader.js
@@ -0,0 +1,131 @@
+"use strict";
+
+/**
+ * Returns the id of the crash minidump.
+ *
+ * @param subject (nsISupports)
+ *        The subject passed through the ipc:content-shutdown
+ *        observer notification when a content process crash has
+ *        occurred.
+ * @returns {String} The crash dump id.
+ */
+function getCrashDumpId(subject) {
+  Assert.ok(
+    subject instanceof Ci.nsIPropertyBag2,
+    "Subject needs to be a nsIPropertyBag2 to clean up properly"
+  );
+
+  return subject.getPropertyAsAString("dumpID");
+}
+
+/**
+ * Cleans up the .dmp and .extra file from a crash.
+ *
+ * @param id {String} The crash dump id.
+ */
+function cleanUpMinidump(id) {
+  let dir = Services.dirsvc.get("ProfD", Ci.nsIFile);
+  dir.append("minidumps");
+
+  let file = dir.clone();
+  file.append(id + ".dmp");
+  file.remove(true);
+
+  file = dir.clone();
+  file.append(id + ".extra");
+  file.remove(true);
+}
+
+/**
+ * This test ensures that if a remote frameloader crashes after
+ * the frameloader owner swaps it out for a new frameloader,
+ * that a oop-browser-crashed event is not sent to the new
+ * frameloader's browser element.
+ */
+add_task(async function test_crash_in_previous_frameloader() {
+  // On debug builds, crashing tabs results in much thinking, which
+  // slows down the test and results in intermittent test timeouts,
+  // so we'll pump up the expected timeout for this test.
+  requestLongerTimeout(2);
+
+  if (!gMultiProcessBrowser) {
+    Assert.ok(false, "This test should only be run in multi-process mode.");
+    return;
+  }
+
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: "http://example.com",
+    },
+    async function(browser) {
+      // First, sanity check...
+      Assert.ok(
+        browser.isRemoteBrowser,
+        "This browser needs to be remote if this test is going to " +
+          "work properly."
+      );
+
+      // We will wait for the oop-browser-crashed event to have
+      // a chance to appear. That event is fired when RemoteTabs
+      // are destroyed, and that occurs _before_ ContentParents
+      // are destroyed, so we'll wait on the ipc:content-shutdown
+      // observer notification, which is fired when a ContentParent
+      // goes away. After we see this notification, oop-browser-crashed
+      // events should have fired.
+      let contentProcessGone = TestUtils.topicObserved("ipc:content-shutdown");
+      let sawTabCrashed = false;
+      let onTabCrashed = () => {
+        sawTabCrashed = true;
+      };
+
+      browser.addEventListener("oop-browser-crashed", onTabCrashed);
+
+      // The name of the game is to cause a crash in a remote browser,
+      // and then immediately swap out the browser for a non-remote one.
+      await SpecialPowers.spawn(browser, [], function() {
+        const { ctypes } = ChromeUtils.import(
+          "resource://gre/modules/ctypes.jsm"
+        );
+
+        let dies = function() {
+          ChromeUtils.privateNoteIntentionalCrash();
+          let zero = new ctypes.intptr_t(8);
+          let badptr = ctypes.cast(zero, ctypes.PointerType(ctypes.int32_t));
+          badptr.contents;
+        };
+
+        // When the parent flips the remoteness of the browser, the
+        // page should receive the pagehide event, which we'll then
+        // use to crash the frameloader.
+        docShell.chromeEventHandler.addEventListener("pagehide", function() {
+          dump("\nEt tu, Brute?\n");
+          dies();
+        });
+      });
+
+      gBrowser.updateBrowserRemoteness(browser, {
+        remoteType: E10SUtils.NOT_REMOTE,
+      });
+      info("Waiting for content process to go away.");
+      let [subject /* , data */] = await contentProcessGone;
+
+      // If we don't clean up the minidump, the harness will
+      // complain.
+      let dumpID = getCrashDumpId(subject);
+
+      Assert.ok(dumpID, "There should be a dumpID");
+      if (dumpID) {
+        await Services.crashmanager.ensureCrashIsPresent(dumpID);
+        cleanUpMinidump(dumpID);
+      }
+
+      info("Content process is gone!");
+      Assert.ok(
+        !sawTabCrashed,
+        "Should not have seen the oop-browser-crashed event."
+      );
+      browser.removeEventListener("oop-browser-crashed", onTabCrashed);
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_datetime_datepicker.js b/toolkit/content/tests/browser/browser_datetime_datepicker.js
new file mode 100644
index 0000000000..a354dda0ec
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_datetime_datepicker.js
@@ -0,0 +1,791 @@
+/* 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/. */
+
+"use strict";
+
+const MONTH_YEAR = ".month-year",
+  DAYS_VIEW = ".days-view",
+  BTN_PREV_MONTH = ".prev",
+  BTN_NEXT_MONTH = ".next";
+const DATE_FORMAT = new Intl.DateTimeFormat("en-US", {
+  year: "numeric",
+  month: "long",
+  timeZone: "UTC",
+}).format;
+const DATE_FORMAT_LOCAL = new Intl.DateTimeFormat("en-US", {
+  year: "numeric",
+  month: "long",
+}).format;
+
+// Create a list of abbreviations for calendar class names
+const W = "weekend",
+  O = "outside",
+  S = "selection",
+  R = "out-of-range",
+  T = "today",
+  P = "off-step";
+
+// Calendar classlist for 2016-12. Used to verify the classNames are correct.
+const calendarClasslist_201612 = [
+  [W, O],
+  [O],
+  [O],
+  [O],
+  [],
+  [],
+  [W],
+  [W],
+  [],
+  [],
+  [],
+  [],
+  [],
+  [W],
+  [W],
+  [],
+  [],
+  [],
+  [S],
+  [],
+  [W],
+  [W],
+  [],
+  [],
+  [],
+  [],
+  [],
+  [W],
+  [W],
+  [],
+  [],
+  [],
+  [],
+  [],
+  [W],
+  [W, O],
+  [O],
+  [O],
+  [O],
+  [O],
+  [O],
+  [W, O],
+];
+
+function getCalendarText() {
+  return helper.getChildren(DAYS_VIEW).map(child => child.textContent);
+}
+
+function getCalendarClassList() {
+  return helper
+    .getChildren(DAYS_VIEW)
+    .map(child => Array.from(child.classList));
+}
+
+function mergeArrays(a, b) {
+  return a.map((classlist, index) => classlist.concat(b[index]));
+}
+
+async function verifyPickerPosition(browsingContext, inputId) {
+  let inputRect = await SpecialPowers.spawn(
+    browsingContext,
+    [inputId],
+    async function(inputIdChild) {
+      let rect = content.document
+        .getElementById(inputIdChild)
+        .getBoundingClientRect();
+      return {
+        left: content.mozInnerScreenX + rect.left,
+        bottom: content.mozInnerScreenY + rect.bottom,
+      };
+    }
+  );
+
+  function is_close(got, exp, msg) {
+    // on some platforms we see differences of a fraction of a pixel - so
+    // allow any difference of < 1 pixels as being OK.
+    ok(
+      Math.abs(got - exp) < 1,
+      msg + ": " + got + " should be equal(-ish) to " + exp
+    );
+  }
+  is_close(helper.panel.screenX, inputRect.left, "datepicker x position");
+  is_close(helper.panel.screenY, inputRect.bottom, "datepicker y position");
+}
+
+let helper = new DateTimeTestHelper();
+
+registerCleanupFunction(() => {
+  helper.cleanup();
+});
+
+/**
+ * Test that date picker opens to today's date when input field is blank
+ */
+add_task(async function test_datepicker_today() {
+  const date = new Date();
+
+  await helper.openPicker("data:text/html, <input type='date'>");
+
+  if (date.getMonth() === new Date().getMonth()) {
+    Assert.equal(
+      helper.getElement(MONTH_YEAR).textContent,
+      DATE_FORMAT_LOCAL(date)
+    );
+  } else {
+    Assert.ok(
+      true,
+      "Skipping datepicker today test if month changes when opening picker."
+    );
+  }
+
+  await helper.tearDown();
+});
+
+/**
+ * Test that date picker opens to the correct month, with calendar days
+ * displayed correctly, given a date value is set.
+ */
+add_task(async function test_datepicker_open() {
+  const inputValue = "2016-12-15";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(inputValue))
+  );
+  Assert.deepEqual(
+    getCalendarText(),
+    [
+      "27",
+      "28",
+      "29",
+      "30",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+      "11",
+      "12",
+      "13",
+      "14",
+      "15",
+      "16",
+      "17",
+      "18",
+      "19",
+      "20",
+      "21",
+      "22",
+      "23",
+      "24",
+      "25",
+      "26",
+      "27",
+      "28",
+      "29",
+      "30",
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+    ],
+    "2016-12"
+  );
+  Assert.deepEqual(
+    getCalendarClassList(),
+    calendarClasslist_201612,
+    "2016-12 classNames"
+  );
+
+  await helper.tearDown();
+});
+
+/**
+ * Ensure picker closes when focus moves to a different input.
+ */
+add_task(async function test_datepicker_focus_change() {
+  await helper.openPicker(
+    `data:text/html,<input id=date type=date><input id=other>`
+  );
+  let browser = helper.tab.linkedBrowser;
+  await verifyPickerPosition(browser, "date");
+
+  isnot(helper.panel.hidden, "Panel should be visible");
+
+  await SpecialPowers.spawn(browser, [], () => {
+    content.document.querySelector("#other").focus();
+  });
+
+  // NOTE: Would be cool to be able to use promisePickerClosed(), but
+  // popuphidden isn't really triggered for this code path it seems, so oh
+  // well.
+  await BrowserTestUtils.waitForCondition(
+    () => helper.panel.hidden,
+    "waiting for close"
+  );
+  await helper.tearDown();
+});
+
+/**
+ * Ensure picker opens and closes with key bindings appropriately.
+ */
+/*
+disabled for bug 1676078
+add_task(async function test_datepicker_keyboard_open() {
+  const inputValue = "2016-12-15";
+  const prevMonth = "2016-11-01";
+  await helper.openPicker(
+    `data:text/html,<input id=date type=date value=${inputValue}>`
+  );
+  let browser = helper.tab.linkedBrowser;
+  await verifyPickerPosition(browser, "date");
+
+  BrowserTestUtils.synthesizeKey(" ", {}, browser);
+
+  await BrowserTestUtils.waitForCondition(
+    () => helper.panel.hidden,
+    "waiting for close"
+  );
+
+  BrowserTestUtils.synthesizeKey(" ", {}, browser);
+
+  await BrowserTestUtils.waitForCondition(
+    () => !helper.panel.hidden,
+    "waiting for open"
+  );
+
+  // NOTE: After the click, the first input field (the month one) is focused,
+  // so down arrow will change the selected month.
+  //
+  // This assumes en-US locale, which seems fine for testing purposes (as
+  // DATE_FORMAT and other bits around do the same).
+  BrowserTestUtils.synthesizeKey("VK_DOWN", {}, browser);
+
+  // It'd be good to use something else than waitForCondition for this but
+  // there's no exposed event atm when the value changes from the child.
+  await BrowserTestUtils.waitForCondition(() => {
+    return (
+      helper.getElement(MONTH_YEAR).textContent ==
+      DATE_FORMAT(new Date(prevMonth))
+    );
+  }, "Should update date when updating months");
+
+  await helper.tearDown();
+});
+*/
+
+/**
+ * When the prev month button is clicked, calendar should display the dates for
+ * the previous month.
+ */
+add_task(async function test_datepicker_prev_month_btn() {
+  const inputValue = "2016-12-15";
+  const prevMonth = "2016-11-01";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+  helper.click(helper.getElement(BTN_PREV_MONTH));
+
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(prevMonth))
+  );
+  Assert.deepEqual(
+    getCalendarText(),
+    [
+      "30",
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+      "11",
+      "12",
+      "13",
+      "14",
+      "15",
+      "16",
+      "17",
+      "18",
+      "19",
+      "20",
+      "21",
+      "22",
+      "23",
+      "24",
+      "25",
+      "26",
+      "27",
+      "28",
+      "29",
+      "30",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+    ],
+    "2016-11"
+  );
+
+  await helper.tearDown();
+});
+
+/**
+ * When the next month button is clicked, calendar should display the dates for
+ * the next month.
+ */
+add_task(async function test_datepicker_next_month_btn() {
+  const inputValue = "2016-12-15";
+  const nextMonth = "2017-01-01";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+  helper.click(helper.getElement(BTN_NEXT_MONTH));
+
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(nextMonth))
+  );
+  Assert.deepEqual(
+    getCalendarText(),
+    [
+      "25",
+      "26",
+      "27",
+      "28",
+      "29",
+      "30",
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+      "11",
+      "12",
+      "13",
+      "14",
+      "15",
+      "16",
+      "17",
+      "18",
+      "19",
+      "20",
+      "21",
+      "22",
+      "23",
+      "24",
+      "25",
+      "26",
+      "27",
+      "28",
+      "29",
+      "30",
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+    ],
+    "2017-01"
+  );
+
+  await helper.tearDown();
+});
+
+/**
+ * When a date on the calendar is clicked, date picker should close and set
+ * value to the input box.
+ */
+add_task(async function test_datepicker_clicked() {
+  const inputValue = "2016-12-15";
+  const firstDayOnCalendar = "2016-11-27";
+
+  await helper.openPicker(
+    `data:text/html, <input id="date" type="date" value="${inputValue}">`
+  );
+
+  let browser = helper.tab.linkedBrowser;
+  await verifyPickerPosition(browser, "date");
+
+  // Click the first item (top-left corner) of the calendar
+  let promise = BrowserTestUtils.waitForContentEvent(
+    helper.tab.linkedBrowser,
+    "input"
+  );
+  helper.click(helper.getElement(DAYS_VIEW).children[0]);
+  await promise;
+
+  let value = await SpecialPowers.spawn(
+    browser,
+    [],
+    () => content.document.querySelector("input").value
+  );
+  Assert.equal(value, firstDayOnCalendar);
+
+  await helper.tearDown();
+});
+
+/**
+ * Ensure that the datepicker popop appears correctly positioned when
+ * the input field has been transformed.
+ */
+add_task(async function test_datepicker_transformed_position() {
+  const inputValue = "2016-12-15";
+
+  const style =
+    "transform: translateX(7px) translateY(13px); border-top: 2px; border-left: 5px; margin: 30px;";
+  const iframeContent = `<input id="date" type="date" value="${inputValue}" style="${style}">`;
+  await helper.openPicker(
+    "data:text/html,<iframe id='iframe' src='http://example.net/document-builder.sjs?html=" +
+      encodeURI(iframeContent) +
+      "'>",
+    true
+  );
+
+  let bc = helper.tab.linkedBrowser.browsingContext.children[0];
+  await verifyPickerPosition(bc, "date");
+
+  await helper.tearDown();
+});
+
+/**
+ * Make sure picker is in correct state when it is reopened.
+ */
+add_task(async function test_datepicker_reopen_state() {
+  const inputValue = "2016-12-15";
+  const nextMonth = "2017-01-01";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+  // Navigate to the next month but does not commit the change
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(inputValue))
+  );
+  helper.click(helper.getElement(BTN_NEXT_MONTH));
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(nextMonth))
+  );
+  EventUtils.synthesizeKey("VK_ESCAPE", {}, window);
+
+  // Ensures the picker opens to the month of the input value
+  await BrowserTestUtils.synthesizeMouseAtCenter(
+    "input",
+    {},
+    gBrowser.selectedBrowser
+  );
+  await helper.waitForPickerReady();
+  Assert.equal(
+    helper.getElement(MONTH_YEAR).textContent,
+    DATE_FORMAT(new Date(inputValue))
+  );
+
+  await helper.tearDown();
+});
+
+/**
+ * When min and max attributes are set, calendar should show some dates as
+ * out-of-range.
+ */
+add_task(async function test_datepicker_min_max() {
+  const inputValue = "2016-12-15";
+  const inputMin = "2016-12-05";
+  const inputMax = "2016-12-25";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}" min="${inputMin}" max="${inputMax}">`
+  );
+
+  Assert.deepEqual(
+    getCalendarClassList(),
+    mergeArrays(calendarClasslist_201612, [
+      // R denotes out-of-range
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+      [R],
+    ]),
+    "2016-12 with min & max"
+  );
+
+  await helper.tearDown();
+});
+
+/**
+ * When step attribute is set, calendar should show some dates as off-step.
+ */
+add_task(async function test_datepicker_step() {
+  const inputValue = "2016-12-15";
+  const inputStep = "5";
+
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}" step="${inputStep}">`
+  );
+
+  Assert.deepEqual(
+    getCalendarClassList(),
+    mergeArrays(calendarClasslist_201612, [
+      // P denotes off-step
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+      [P],
+      [],
+      [P],
+      [P],
+      [P],
+    ]),
+    "2016-12 with step"
+  );
+
+  await helper.tearDown();
+});
+
+add_task(async function test_datepicker_abs_min() {
+  const inputValue = "0001-01-01";
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+
+  Assert.deepEqual(
+    getCalendarText(),
+    [
+      "",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+      "11",
+      "12",
+      "13",
+      "14",
+      "15",
+      "16",
+      "17",
+      "18",
+      "19",
+      "20",
+      "21",
+      "22",
+      "23",
+      "24",
+      "25",
+      "26",
+      "27",
+      "28",
+      "29",
+      "30",
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+    ],
+    "0001-01"
+  );
+
+  await helper.tearDown();
+});
+
+// This test checks if the change event is considered as user input event.
+add_task(async function test_datepicker_handling_user_input() {
+  await helper.openPicker(`data:text/html, <input type="date">`);
+
+  let changeEventPromise = SpecialPowers.spawn(
+    helper.tab.linkedBrowser,
+    [],
+    async () => {
+      let input = content.document.querySelector("input");
+      await ContentTaskUtils.waitForEvent(input, "change", false, e => {
+        ok(
+          content.window.windowUtils.isHandlingUserInput,
+          "isHandlingUserInput should be true"
+        );
+        return true;
+      });
+    }
+  );
+  // Click the first item (top-left corner) of the calendar
+  helper.click(helper.getElement(DAYS_VIEW).children[0]);
+  await changeEventPromise;
+
+  await helper.tearDown();
+});
+
+add_task(async function test_datepicker_abs_max() {
+  const inputValue = "275760-09-13";
+  await helper.openPicker(
+    `data:text/html, <input type="date" value="${inputValue}">`
+  );
+
+  Assert.deepEqual(
+    getCalendarText(),
+    [
+      "31",
+      "1",
+      "2",
+      "3",
+      "4",
+      "5",
+      "6",
+      "7",
+      "8",
+      "9",
+      "10",
+      "11",
+      "12",
+      "13",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+      "",
+    ],
+    "275760-09"
+  );
+
+  await helper.tearDown();
+});
diff --git a/toolkit/content/tests/browser/browser_default_image_filename.js b/toolkit/content/tests/browser/browser_default_image_filename.js
new file mode 100644
index 0000000000..dc6eb8559e
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_default_image_filename.js
@@ -0,0 +1,61 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+var MockFilePicker = SpecialPowers.MockFilePicker;
+MockFilePicker.init(window);
+
+/**
+ * TestCase for bug 564387
+ * <https://bugzilla.mozilla.org/show_bug.cgi?id=564387>
+ */
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url:
+        "data:image/gif;base64,R0lGODlhEAAOALMAAOazToeHh0tLS/7LZv/0jvb29t/f3//Ub//ge8WSLf/rhf/3kdbW1mxsbP//mf///yH5BAAAAAAALAAAAAAQAA4AAARe8L1Ekyky67QZ1hLnjM5UUde0ECwLJoExKcppV0aCcGCmTIHEIUEqjgaORCMxIC6e0CcguWw6aFjsVMkkIr7g77ZKPJjPZqIyd7sJAgVGoEGv2xsBxqNgYPj/gAwXEQA7",
+    },
+    async function(browser) {
+      let popupShownPromise = BrowserTestUtils.waitForEvent(
+        document,
+        "popupshown"
+      );
+
+      await BrowserTestUtils.synthesizeMouseAtCenter(
+        "img",
+        {
+          type: "contextmenu",
+          button: 2,
+        },
+        browser
+      );
+
+      await popupShownPromise;
+
+      let showFilePickerPromise = new Promise(resolve => {
+        MockFilePicker.showCallback = function(fp) {
+          is(fp.defaultString, "index.gif");
+          resolve();
+        };
+      });
+
+      registerCleanupFunction(function() {
+        MockFilePicker.cleanup();
+      });
+
+      // Select "Save Image As" option from context menu
+      var saveImageAsCommand = document.getElementById("context-saveimage");
+      saveImageAsCommand.doCommand();
+
+      await showFilePickerPromise;
+
+      let contextMenu = document.getElementById("contentAreaContextMenu");
+      let popupHiddenPromise = BrowserTestUtils.waitForEvent(
+        contextMenu,
+        "popuphidden"
+      );
+      contextMenu.hidePopup();
+      await popupHiddenPromise;
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_default_image_filename_redirect.js b/toolkit/content/tests/browser/browser_default_image_filename_redirect.js
new file mode 100644
index 0000000000..a17d3dc3ee
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_default_image_filename_redirect.js
@@ -0,0 +1,53 @@
+/**
+ * TestCase for bug 1406253
+ * <https://bugzilla.mozilla.org/show_bug.cgi?id=1406253>
+ *
+ * Load firebird.png, redirect it to doggy.png, and verify the filename is
+ * doggy.png in file picker dialog.
+ */
+
+let MockFilePicker = SpecialPowers.MockFilePicker;
+MockFilePicker.init(window);
+add_task(async function() {
+  // This URL will redirect to doggy.png.
+  const URL_FIREBIRD =
+    "http://mochi.test:8888/browser/toolkit/content/tests/browser/firebird.png";
+
+  await BrowserTestUtils.withNewTab(URL_FIREBIRD, async function(browser) {
+    // Click image to show context menu.
+    let popupShownPromise = BrowserTestUtils.waitForEvent(
+      document,
+      "popupshown"
+    );
+    await BrowserTestUtils.synthesizeMouseAtCenter(
+      "img",
+      { type: "contextmenu", button: 2 },
+      browser
+    );
+    await popupShownPromise;
+
+    // Prepare mock file picker.
+    let showFilePickerPromise = new Promise(resolve => {
+      MockFilePicker.showCallback = fp => resolve(fp.defaultString);
+    });
+    registerCleanupFunction(function() {
+      MockFilePicker.cleanup();
+    });
+
+    // Select "Save Image As" option from context menu
+    var saveImageAsCommand = document.getElementById("context-saveimage");
+    saveImageAsCommand.doCommand();
+
+    let filename = await showFilePickerPromise;
+    is(filename, "doggy.png", "Verify image filename.");
+
+    // Close context menu.
+    let contextMenu = document.getElementById("contentAreaContextMenu");
+    let popupHiddenPromise = BrowserTestUtils.waitForEvent(
+      contextMenu,
+      "popuphidden"
+    );
+    contextMenu.hidePopup();
+    await popupHiddenPromise;
+  });
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_media.js b/toolkit/content/tests/browser/browser_delay_autoplay_media.js
new file mode 100644
index 0000000000..acaf4ed16a
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_media.js
@@ -0,0 +1,145 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_multipleAudio.html";
+const PAGE_NO_AUTOPLAY =
+  "https://example.com/browser/toolkit/content/tests/browser/file_nonAutoplayAudio.html";
+
+function check_audio_paused(browser, shouldBePaused) {
+  return SpecialPowers.spawn(browser, [shouldBePaused], shouldBePaused => {
+    var autoPlay = content.document.getElementById("autoplay");
+    if (!autoPlay) {
+      ok(false, "Can't get the audio element!");
+    }
+    is(
+      autoPlay.paused,
+      shouldBePaused,
+      "autoplay audio should " + (!shouldBePaused ? "not " : "") + "be paused."
+    );
+  });
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+function set_media_autoplay() {
+  let audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+    return;
+  }
+  audio.autoplay = true;
+}
+
+add_task(async function delay_media_with_autoplay_keyword() {
+  info("- open new background tab -");
+  const tab = BrowserTestUtils.addTab(window.gBrowser, PAGE_NO_AUTOPLAY);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- set media's autoplay property -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [], set_media_autoplay);
+
+  info("- should delay autoplay media -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- switch tab to foreground -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- media should be resumed because tab has been visited -");
+  await waitForTabPlayingEvent(tab, true);
+  await waitForTabBlockEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function delay_media_with_play_invocation() {
+  info("- open new background tab1 -");
+  let tab1 = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab1.linkedBrowser);
+
+  info("- should delay autoplay media for non-visited tab1 -");
+  await waitForTabBlockEvent(tab1, true);
+
+  info("- open new background tab2 -");
+  let tab2 = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab2.linkedBrowser);
+
+  info("- should delay autoplay for non-visited tab2 -");
+  await waitForTabBlockEvent(tab2, true);
+
+  info("- switch to tab1 -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab1);
+
+  info("- media in tab1 should be unblocked because the tab was visited -");
+  await waitForTabPlayingEvent(tab1, true);
+  await waitForTabBlockEvent(tab1, false);
+
+  info("- open another new foreground tab3 -");
+  let tab3 = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    "about:blank"
+  );
+  info("- should still play media from tab1 -");
+  await waitForTabPlayingEvent(tab1, true);
+
+  info("- should still block media from tab2 -");
+  await waitForTabPlayingEvent(tab2, false);
+  await waitForTabBlockEvent(tab2, true);
+
+  info("- remove tabs -");
+  BrowserTestUtils.removeTab(tab1);
+  BrowserTestUtils.removeTab(tab2);
+  BrowserTestUtils.removeTab(tab3);
+});
+
+add_task(async function resume_delayed_media_when_enable_blocking_autoplay() {
+  // Disable autoplay and verify that when a tab is opened in the
+  // background and has had its playback start delayed, resuming via the audio
+  // tab indicator overrides the autoplay blocking logic.
+  //
+  // Clicking "play" on the audio tab indicator should always start playback
+  // in that tab, even if it's in an autoplay-blocked origin.
+  //
+  // Also test that that this block-autoplay logic override doesn't survive
+  // a new document being loaded into the tab; the new document should have
+  // to satisfy the autoplay requirements on its own.
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.autoplay.default", SpecialPowers.Ci.nsIAutoplay.BLOCKED],
+      ["media.autoplay.blocking_policy", 0],
+    ],
+  });
+
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- should block autoplay for non-visited tab -");
+  await waitForTabBlockEvent(tab, true);
+  await check_audio_paused(tab.linkedBrowser, true);
+  tab.linkedBrowser.resumeMedia();
+
+  info("- should not block media from tab -");
+  await waitForTabPlayingEvent(tab, true);
+  await check_audio_paused(tab.linkedBrowser, false);
+
+  info(
+    "- check that loading a new URI in page clears gesture activation status -"
+  );
+  BrowserTestUtils.loadURI(tab.linkedBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- should block autoplay again as gesture activation status cleared -");
+  await check_audio_paused(tab.linkedBrowser, true);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+
+  // Clear the block-autoplay pref.
+  await SpecialPowers.popPrefEnv();
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_media_pausedAfterPlay.js b/toolkit/content/tests/browser/browser_delay_autoplay_media_pausedAfterPlay.js
new file mode 100644
index 0000000000..09dc5f9691
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_media_pausedAfterPlay.js
@@ -0,0 +1,121 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_nonAutoplayAudio.html";
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+/**
+ * When media starts in an unvisited tab, we would delay its playback and resume
+ * media playback when the tab goes to foreground first time. There are two test
+ * cases are used to check different situations.
+ *
+ * The first one is used to check if the delayed media has been paused before
+ * the tab goes to foreground. Then, when the tab goes to foreground, media
+ * should still be paused.
+ *
+ * The second one is used to check if the delayed media has been paused, but
+ * it eventually was started again before the tab goes to foreground. Then, when
+ * the tab goes to foreground, media should be resumed.
+ */
+add_task(async function testShouldNotResumePausedMedia() {
+  info("- open new background tab and wait until it finishes loading -");
+  const tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- play media and then immediately pause it -");
+  await doPlayThenPauseOnMedia(tab);
+
+  info("- show delay media playback icon on tab -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- selecting tab as foreground tab would resume the tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- resuming tab should dismiss delay autoplay icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- paused media should still be paused -");
+  await checkAudioPauseState(tab, true /* should be paused */);
+
+  info("- paused media won't generate tab playing icon -");
+  await waitForTabPlayingEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function testShouldResumePlayedMedia() {
+  info("- open new background tab and wait until it finishes loading -");
+  const tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- play media, pause it, then play it again -");
+  await doPlayPauseThenPlayOnMedia(tab);
+
+  info("- show delay media playback icon on tab -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- select tab as foreground tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- resuming tab should dismiss delay autoplay icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- played media should still be played -");
+  await checkAudioPauseState(tab, false /* should be played */);
+
+  info("- played media would generate tab playing icon -");
+  await waitForTabPlayingEvent(tab, true);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
+
+/**
+ * Helper functions.
+ */
+async function checkAudioPauseState(tab, expectedPaused) {
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [expectedPaused],
+    expectedPaused => {
+      const audio = content.document.getElementById("testAudio");
+      if (!audio) {
+        ok(false, "Can't get the audio element!");
+      }
+
+      is(audio.paused, expectedPaused, "The pause state of audio is corret.");
+    }
+  );
+}
+
+async function doPlayThenPauseOnMedia(tab) {
+  await SpecialPowers.spawn(tab.linkedBrowser, [], () => {
+    const audio = content.document.getElementById("testAudio");
+    if (!audio) {
+      ok(false, "Can't get the audio element!");
+    }
+
+    audio.play();
+    audio.pause();
+  });
+}
+
+async function doPlayPauseThenPlayOnMedia(tab) {
+  await SpecialPowers.spawn(tab.linkedBrowser, [], () => {
+    const audio = content.document.getElementById("testAudio");
+    if (!audio) {
+      ok(false, "Can't get the audio element!");
+    }
+
+    audio.play();
+    audio.pause();
+    audio.play();
+  });
+}
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_multipleMedia.js b/toolkit/content/tests/browser/browser_delay_autoplay_multipleMedia.js
new file mode 100644
index 0000000000..3d60156cf1
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_multipleMedia.js
@@ -0,0 +1,77 @@
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_multipleAudio.html";
+
+function check_autoplay_audio_onplay() {
+  let autoPlay = content.document.getElementById("autoplay");
+  if (!autoPlay) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  return new Promise((resolve, reject) => {
+    autoPlay.onplay = () => {
+      ok(false, "Should not receive play event!");
+      this.onplay = null;
+      reject();
+    };
+
+    autoPlay.pause();
+    autoPlay.play();
+
+    content.setTimeout(() => {
+      ok(true, "Doesn't receive play event when media was blocked.");
+      autoPlay.onplay = null;
+      resolve();
+    }, 1000);
+  });
+}
+
+function play_nonautoplay_audio_should_be_blocked() {
+  let nonAutoPlay = content.document.getElementById("nonautoplay");
+  if (!nonAutoPlay) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  nonAutoPlay.play();
+  ok(nonAutoPlay.paused, "The blocked audio can't be playback.");
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+add_task(async function block_multiple_media() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  let browser = tab.linkedBrowser;
+  BrowserTestUtils.loadURI(browser, PAGE);
+  await BrowserTestUtils.browserLoaded(browser);
+
+  info("- tab should be blocked -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- autoplay media should be blocked -");
+  await SpecialPowers.spawn(browser, [], check_autoplay_audio_onplay);
+
+  info("- non-autoplay can't start playback when the tab is blocked -");
+  await SpecialPowers.spawn(
+    browser,
+    [],
+    play_nonautoplay_audio_should_be_blocked
+  );
+
+  info("- select tab as foreground tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- tab should be resumed -");
+  await waitForTabPlayingEvent(tab, true);
+  await waitForTabBlockEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_notInTreeAudio.js b/toolkit/content/tests/browser/browser_delay_autoplay_notInTreeAudio.js
new file mode 100644
index 0000000000..c1cca96b2d
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_notInTreeAudio.js
@@ -0,0 +1,66 @@
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_nonAutoplayAudio.html";
+
+function check_audio_pause_state(expectPause) {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  is(audio.paused, expectPause, "The pause state of audio is corret.");
+}
+
+function play_not_in_tree_audio() {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  content.document.body.removeChild(audio);
+
+  // Add timeout to ensure the audio is removed from DOM tree.
+  content.setTimeout(function() {
+    info("Prepare to start playing audio.");
+    audio.play();
+  }, 1000);
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+add_task(async function block_not_in_tree_media() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- tab should not be blocked -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- check audio's playing state -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [true], check_audio_pause_state);
+
+  info("- playing audio -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [], play_not_in_tree_audio);
+
+  info("- tab should be blocked -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- switch tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- tab should be resumed -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- tab should be audible -");
+  await waitForTabPlayingEvent(tab, true);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_playAfterTabVisible.js b/toolkit/content/tests/browser/browser_delay_autoplay_playAfterTabVisible.js
new file mode 100644
index 0000000000..e1f3f8f814
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_playAfterTabVisible.js
@@ -0,0 +1,68 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_nonAutoplayAudio.html";
+
+function check_audio_pause_state(expectPause) {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  is(audio.paused, expectPause, "The pause state of audio is corret.");
+}
+
+function play_audio() {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  audio.play();
+  return new Promise(resolve => {
+    audio.onplay = function() {
+      audio.onplay = null;
+      ok(true, "Audio starts playing.");
+      resolve();
+    };
+  });
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+/**
+ * This test is used for testing the visible tab which was not resumed yet.
+ * If the tab doesn't have any media component, it won't be resumed even it
+ * has already gone to foreground until we start audio.
+ */
+add_task(async function media_should_be_able_to_play_in_visible_tab() {
+  info("- open new background tab, and check tab's media pause state -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+  await SpecialPowers.spawn(tab.linkedBrowser, [true], check_audio_pause_state);
+
+  info(
+    "- select tab as foreground tab, and tab's media should still be paused -"
+  );
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+  await SpecialPowers.spawn(tab.linkedBrowser, [true], check_audio_pause_state);
+
+  info("- start audio in tab -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [], play_audio);
+
+  info("- audio should be playing -");
+  await waitForTabBlockEvent(tab, false);
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [false],
+    check_audio_pause_state
+  );
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_playMediaInMuteTab.js b/toolkit/content/tests/browser/browser_delay_autoplay_playMediaInMuteTab.js
new file mode 100644
index 0000000000..c333021697
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_playMediaInMuteTab.js
@@ -0,0 +1,97 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_nonAutoplayAudio.html";
+
+function wait_for_event(browser, event) {
+  return BrowserTestUtils.waitForEvent(browser, event, false, event => {
+    is(
+      event.originalTarget,
+      browser,
+      "Event must be dispatched to correct browser."
+    );
+    return true;
+  });
+}
+
+function check_audio_volume_and_mute(expectedMute) {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  let expectedVolume = expectedMute ? 0.0 : 1.0;
+  is(expectedVolume, audio.computedVolume, "Audio's volume is correct!");
+  is(expectedMute, audio.computedMuted, "Audio's mute state is correct!");
+}
+
+function check_audio_pause_state(expectedPauseState) {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  is(audio.paused, expectedPauseState, "Audio is paused.");
+}
+
+function play_audio() {
+  var audio = content.document.getElementById("testAudio");
+  if (!audio) {
+    ok(false, "Can't get the audio element!");
+  }
+
+  audio.play();
+  ok(audio.paused, "Can't play audio, because the tab was still blocked.");
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+add_task(async function unblock_icon_should_disapear_after_resume_tab() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- audio doesn't be started in beginning -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [true], check_audio_pause_state);
+
+  info("- audio shouldn't be muted -");
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [false],
+    check_audio_volume_and_mute
+  );
+
+  info("- tab shouldn't display unblocking icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- mute tab -");
+  tab.linkedBrowser.mute();
+  ok(tab.linkedBrowser.audioMuted, "Audio should be muted now");
+
+  info("- try to start audio in background tab -");
+  await SpecialPowers.spawn(tab.linkedBrowser, [], play_audio);
+
+  info("- tab should display unblocking icon -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- select tab as foreground tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- audio shoule be muted, but not be blocked -");
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [true],
+    check_audio_volume_and_mute
+  );
+
+  info("- tab should not display unblocking icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_silentAudioTrack_media.js b/toolkit/content/tests/browser/browser_delay_autoplay_silentAudioTrack_media.js
new file mode 100644
index 0000000000..24b48d4999
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_silentAudioTrack_media.js
@@ -0,0 +1,63 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_silentAudioTrack.html";
+
+async function click_unblock_icon(tab) {
+  let icon = tab.soundPlayingIcon;
+
+  await hover_icon(icon, document.getElementById("tabbrowser-tab-tooltip"));
+  EventUtils.synthesizeMouseAtCenter(icon, { button: 0 });
+  leave_icon(icon);
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+add_task(async function unblock_icon_should_disapear_after_resume_tab() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  BrowserTestUtils.loadURI(tab.linkedBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- tab should display unblocking icon -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- select tab as foreground tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- should not display unblocking icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- should not display sound indicator icon -");
+  await waitForTabPlayingEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function should_not_show_sound_indicator_after_resume_tab() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  BrowserTestUtils.loadURI(tab.linkedBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- tab should display unblocking icon -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- click play tab icon -");
+  await click_unblock_icon(tab);
+
+  info("- should not display unblocking icon -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- should not display sound indicator icon -");
+  await waitForTabPlayingEvent(tab, false);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_delay_autoplay_webAudio.js b/toolkit/content/tests/browser/browser_delay_autoplay_webAudio.js
new file mode 100644
index 0000000000..8758cf2629
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_delay_autoplay_webAudio.js
@@ -0,0 +1,40 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_webAudio.html";
+
+// The tab closing code leaves an uncaught rejection. This test has been
+// whitelisted until the issue is fixed.
+if (!gMultiProcessBrowser) {
+  ChromeUtils.import("resource://testing-common/PromiseTestUtils.jsm", this);
+  PromiseTestUtils.expectUncaughtRejection(/is no longer, usable/);
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.useAudioChannelService.testing", true],
+      ["media.block-autoplay-until-in-foreground", true],
+    ],
+  });
+});
+
+add_task(async function block_web_audio() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  BrowserTestUtils.loadURI(tab.linkedBrowser, PAGE);
+  await BrowserTestUtils.browserLoaded(tab.linkedBrowser);
+
+  info("- tab should be blocked -");
+  await waitForTabBlockEvent(tab, true);
+
+  info("- switch tab -");
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+
+  info("- tab should be resumed -");
+  await waitForTabBlockEvent(tab, false);
+
+  info("- tab should be audible -");
+  await waitForTabPlayingEvent(tab, true);
+
+  info("- remove tab -");
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_f7_caret_browsing.js b/toolkit/content/tests/browser/browser_f7_caret_browsing.js
new file mode 100644
index 0000000000..334d40a1f8
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_f7_caret_browsing.js
@@ -0,0 +1,278 @@
+var gListener = null;
+const kURL =
+  "data:text/html;charset=utf-8,Caret browsing is fun.<input id='in'>";
+
+const kPrefShortcutEnabled = "accessibility.browsewithcaret_shortcut.enabled";
+const kPrefWarnOnEnable = "accessibility.warn_on_browsewithcaret";
+const kPrefCaretBrowsingOn = "accessibility.browsewithcaret";
+
+var oldPrefs = {};
+for (let pref of [
+  kPrefShortcutEnabled,
+  kPrefWarnOnEnable,
+  kPrefCaretBrowsingOn,
+]) {
+  oldPrefs[pref] = Services.prefs.getBoolPref(pref);
+}
+
+Services.prefs.setBoolPref(kPrefShortcutEnabled, true);
+Services.prefs.setBoolPref(kPrefWarnOnEnable, true);
+Services.prefs.setBoolPref(kPrefCaretBrowsingOn, false);
+
+registerCleanupFunction(function() {
+  for (let pref of [
+    kPrefShortcutEnabled,
+    kPrefWarnOnEnable,
+    kPrefCaretBrowsingOn,
+  ]) {
+    Services.prefs.setBoolPref(pref, oldPrefs[pref]);
+  }
+});
+
+// NB: not using BrowserTestUtils.domWindowOpened here because there's no way to
+// undo waiting for a window open. If we don't want the window to be opened, and
+// wait for it to verify that it indeed does not open, we need to be able to
+// then "stop" waiting so that when we next *do* want it to open, our "old"
+// listener doesn't fire and do things we don't want (like close the window...).
+let gCaretPromptOpeningObserver;
+function promiseCaretPromptOpened() {
+  return new Promise(resolve => {
+    function observer(subject, topic, data) {
+      if (topic == "domwindowopened") {
+        Services.ww.unregisterNotification(observer);
+        let win = subject;
+        BrowserTestUtils.waitForEvent(
+          win,
+          "load",
+          false,
+          e => e.target.location.href != "about:blank"
+        ).then(() => resolve(win));
+        gCaretPromptOpeningObserver = null;
+      }
+    }
+    Services.ww.registerNotification(observer);
+    gCaretPromptOpeningObserver = observer;
+  });
+}
+
+function hitF7(async = true) {
+  let f7 = () => EventUtils.sendKey("F7");
+  // Need to not stop execution inside this task:
+  if (async) {
+    executeSoon(f7);
+  } else {
+    f7();
+  }
+}
+
+function syncToggleCaretNoDialog(expected) {
+  let openedDialog = false;
+  promiseCaretPromptOpened().then(function(win) {
+    openedDialog = true;
+    win.close(); // This will eventually return focus here and allow the test to continue...
+  });
+  // Cause the dialog to appear sync, if it still does.
+  hitF7(false);
+
+  let expectedStr = expected ? "on." : "off.";
+  ok(
+    !openedDialog,
+    "Shouldn't open a dialog to turn caret browsing " + expectedStr
+  );
+  // Need to clean up if the dialog wasn't opened, so the observer doesn't get
+  // re-triggered later on causing "issues".
+  if (!openedDialog) {
+    Services.ww.unregisterNotification(gCaretPromptOpeningObserver);
+    gCaretPromptOpeningObserver = null;
+  }
+  let prefVal = Services.prefs.getBoolPref(kPrefCaretBrowsingOn);
+  is(prefVal, expected, "Caret browsing should now be " + expectedStr);
+}
+
+function waitForFocusOnInput(browser) {
+  return SpecialPowers.spawn(browser, [], async function() {
+    let textEl = content.document.getElementById("in");
+    return ContentTaskUtils.waitForCondition(() => {
+      return content.document.activeElement == textEl;
+    }, "Input should get focused.");
+  });
+}
+
+function focusInput(browser) {
+  return SpecialPowers.spawn(browser, [], async function() {
+    let textEl = content.document.getElementById("in");
+    textEl.focus();
+  });
+}
+
+add_task(async function checkTogglingCaretBrowsing() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kURL);
+  await focusInput(tab.linkedBrowser);
+
+  let promiseGotKey = promiseCaretPromptOpened();
+  hitF7();
+  let prompt = await promiseGotKey;
+  let doc = prompt.document;
+  let dialog = doc.getElementById("commonDialog");
+  is(dialog.defaultButton, "cancel", "No button should be the default");
+  ok(
+    !doc.getElementById("checkbox").checked,
+    "Checkbox shouldn't be checked by default."
+  );
+  let promiseDialogUnloaded = BrowserTestUtils.waitForEvent(prompt, "unload");
+
+  dialog.cancelDialog();
+  await promiseDialogUnloaded;
+  info("Dialog unloaded");
+  await waitForFocusOnInput(tab.linkedBrowser);
+  ok(
+    !Services.prefs.getBoolPref(kPrefCaretBrowsingOn),
+    "Caret browsing should still be off after cancelling the dialog."
+  );
+
+  promiseGotKey = promiseCaretPromptOpened();
+  hitF7();
+  prompt = await promiseGotKey;
+
+  doc = prompt.document;
+  dialog = doc.getElementById("commonDialog");
+  is(dialog.defaultButton, "cancel", "No button should be the default");
+  ok(
+    !doc.getElementById("checkbox").checked,
+    "Checkbox shouldn't be checked by default."
+  );
+  promiseDialogUnloaded = BrowserTestUtils.waitForEvent(prompt, "unload");
+
+  dialog.acceptDialog();
+  await promiseDialogUnloaded;
+  info("Dialog unloaded");
+  await waitForFocusOnInput(tab.linkedBrowser);
+  ok(
+    Services.prefs.getBoolPref(kPrefCaretBrowsingOn),
+    "Caret browsing should be on after accepting the dialog."
+  );
+
+  syncToggleCaretNoDialog(false);
+
+  promiseGotKey = promiseCaretPromptOpened();
+  hitF7();
+  prompt = await promiseGotKey;
+  doc = prompt.document;
+  dialog = doc.getElementById("commonDialog");
+
+  is(dialog.defaultButton, "cancel", "No button should be the default");
+  ok(
+    !doc.getElementById("checkbox").checked,
+    "Checkbox shouldn't be checked by default."
+  );
+
+  promiseDialogUnloaded = BrowserTestUtils.waitForEvent(prompt, "unload");
+  dialog.cancelDialog();
+  await promiseDialogUnloaded;
+  info("Dialog unloaded");
+  await waitForFocusOnInput(tab.linkedBrowser);
+
+  ok(
+    !Services.prefs.getBoolPref(kPrefCaretBrowsingOn),
+    "Caret browsing should still be off after cancelling the dialog."
+  );
+
+  Services.prefs.setBoolPref(kPrefShortcutEnabled, true);
+  Services.prefs.setBoolPref(kPrefWarnOnEnable, true);
+  Services.prefs.setBoolPref(kPrefCaretBrowsingOn, false);
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function toggleCheckboxNoCaretBrowsing() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kURL);
+  await focusInput(tab.linkedBrowser);
+
+  let promiseGotKey = promiseCaretPromptOpened();
+  hitF7();
+  let prompt = await promiseGotKey;
+  let doc = prompt.document;
+  let dialog = doc.getElementById("commonDialog");
+  is(dialog.defaultButton, "cancel", "No button should be the default");
+  let checkbox = doc.getElementById("checkbox");
+  ok(!checkbox.checked, "Checkbox shouldn't be checked by default.");
+
+  // Check the box:
+  checkbox.click();
+
+  let promiseDialogUnloaded = BrowserTestUtils.waitForEvent(prompt, "unload");
+
+  // Say no:
+  dialog.getButton("cancel").click();
+
+  await promiseDialogUnloaded;
+  info("Dialog unloaded");
+  await waitForFocusOnInput(tab.linkedBrowser);
+  ok(
+    !Services.prefs.getBoolPref(kPrefCaretBrowsingOn),
+    "Caret browsing should still be off."
+  );
+  ok(
+    !Services.prefs.getBoolPref(kPrefShortcutEnabled),
+    "Shortcut should now be disabled."
+  );
+
+  syncToggleCaretNoDialog(false);
+  ok(
+    !Services.prefs.getBoolPref(kPrefShortcutEnabled),
+    "Shortcut should still be disabled."
+  );
+
+  Services.prefs.setBoolPref(kPrefShortcutEnabled, true);
+  Services.prefs.setBoolPref(kPrefWarnOnEnable, true);
+  Services.prefs.setBoolPref(kPrefCaretBrowsingOn, false);
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+add_task(async function toggleCheckboxWantCaretBrowsing() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, kURL);
+  await focusInput(tab.linkedBrowser);
+
+  let promiseGotKey = promiseCaretPromptOpened();
+  hitF7();
+  let prompt = await promiseGotKey;
+  let doc = prompt.document;
+  let dialog = doc.getElementById("commonDialog");
+  is(dialog.defaultButton, "cancel", "No button should be the default");
+  let checkbox = doc.getElementById("checkbox");
+  ok(!checkbox.checked, "Checkbox shouldn't be checked by default.");
+
+  // Check the box:
+  checkbox.click();
+
+  let promiseDialogUnloaded = BrowserTestUtils.waitForEvent(prompt, "unload");
+
+  // Say yes:
+  dialog.acceptDialog();
+  await promiseDialogUnloaded;
+  info("Dialog unloaded");
+  await waitForFocusOnInput(tab.linkedBrowser);
+  ok(
+    Services.prefs.getBoolPref(kPrefCaretBrowsingOn),
+    "Caret browsing should now be on."
+  );
+  ok(
+    Services.prefs.getBoolPref(kPrefShortcutEnabled),
+    "Shortcut should still be enabled."
+  );
+  ok(
+    !Services.prefs.getBoolPref(kPrefWarnOnEnable),
+    "Should no longer warn when enabling."
+  );
+
+  syncToggleCaretNoDialog(false);
+  syncToggleCaretNoDialog(true);
+  syncToggleCaretNoDialog(false);
+
+  Services.prefs.setBoolPref(kPrefShortcutEnabled, true);
+  Services.prefs.setBoolPref(kPrefWarnOnEnable, true);
+  Services.prefs.setBoolPref(kPrefCaretBrowsingOn, false);
+
+  BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_findbar.js b/toolkit/content/tests/browser/browser_findbar.js
new file mode 100644
index 0000000000..b6f116245e
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_findbar.js
@@ -0,0 +1,523 @@
+/* eslint-disable mozilla/no-arbitrary-setTimeout */
+ChromeUtils.import("resource://gre/modules/Timer.jsm", this);
+
+const TEST_PAGE_URI = "data:text/html;charset=utf-8,The letter s.";
+// Using 'javascript' schema to bypass E10SUtils.canLoadURIInRemoteType, because
+// it does not allow 'data:' URI to be loaded in the parent process.
+const E10S_PARENT_TEST_PAGE_URI =
+  getRootDirectory(gTestPath) + "file_empty.html";
+const TEST_PAGE_URI_WITHIFRAME =
+  "https://example.com/browser/toolkit/content/tests/browser/file_findinframe.html";
+
+/**
+ * Makes sure that the findbar hotkeys (' and /) event listeners
+ * are added to the system event group and do not get blocked
+ * by calling stopPropagation on a keypress event on a page.
+ */
+add_task(async function test_hotkey_event_propagation() {
+  info("Ensure hotkeys are not affected by stopPropagation.");
+
+  // Opening new tab
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+  let browser = gBrowser.getBrowserForTab(tab);
+  let findbar = await gBrowser.getFindBar();
+
+  // Pressing these keys open the findbar.
+  const HOTKEYS = ["/", "'"];
+
+  // Checking if findbar appears when any hotkey is pressed.
+  for (let key of HOTKEYS) {
+    is(findbar.hidden, true, "Findbar is hidden now.");
+    gBrowser.selectedTab = tab;
+    await SimpleTest.promiseFocus(gBrowser.selectedBrowser);
+    await BrowserTestUtils.sendChar(key, browser);
+    is(findbar.hidden, false, "Findbar should not be hidden.");
+    await closeFindbarAndWait(findbar);
+  }
+
+  // Stop propagation for all keyboard events.
+  await SpecialPowers.spawn(browser, [], () => {
+    const stopPropagation = e => {
+      e.stopImmediatePropagation();
+    };
+    let window = content.document.defaultView;
+    window.addEventListener("keydown", stopPropagation);
+    window.addEventListener("keypress", stopPropagation);
+    window.addEventListener("keyup", stopPropagation);
+  });
+
+  // Checking if findbar still appears when any hotkey is pressed.
+  for (let key of HOTKEYS) {
+    is(findbar.hidden, true, "Findbar is hidden now.");
+    gBrowser.selectedTab = tab;
+    await SimpleTest.promiseFocus(gBrowser.selectedBrowser);
+    await BrowserTestUtils.sendChar(key, browser);
+    is(findbar.hidden, false, "Findbar should not be hidden.");
+    await closeFindbarAndWait(findbar);
+  }
+
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function test_not_found() {
+  info("Check correct 'Phrase not found' on new tab");
+
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+
+  // Search for the first word.
+  await promiseFindFinished("--- THIS SHOULD NEVER MATCH ---", false);
+  let findbar = gBrowser.getCachedFindBar();
+  is(
+    findbar._findStatusDesc.textContent,
+    findbar._notFoundStr,
+    "Findbar status text should be 'Phrase not found'"
+  );
+
+  gBrowser.removeTab(tab);
+});
+
+add_task(async function test_found() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+
+  // Search for a string that WILL be found, with 'Highlight All' on
+  await promiseFindFinished("S", true);
+  ok(
+    !gBrowser.getCachedFindBar()._findStatusDesc.textContent,
+    "Findbar status should be empty"
+  );
+
+  gBrowser.removeTab(tab);
+});
+
+// Setting first findbar to case-sensitive mode should not affect
+// new tab find bar.
+add_task(async function test_tabwise_case_sensitive() {
+  let tab1 = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+  let findbar1 = await gBrowser.getFindBar();
+
+  let tab2 = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+  let findbar2 = await gBrowser.getFindBar();
+
+  // Toggle case sensitivity for first findbar
+  findbar1.getElement("find-case-sensitive").click();
+
+  gBrowser.selectedTab = tab1;
+
+  // Not found for first tab.
+  await promiseFindFinished("S", true);
+  is(
+    findbar1._findStatusDesc.textContent,
+    findbar1._notFoundStr,
+    "Findbar status text should be 'Phrase not found'"
+  );
+
+  gBrowser.selectedTab = tab2;
+
+  // But it didn't affect the second findbar.
+  await promiseFindFinished("S", true);
+  ok(!findbar2._findStatusDesc.textContent, "Findbar status should be empty");
+
+  gBrowser.removeTab(tab1);
+  gBrowser.removeTab(tab2);
+});
+
+/**
+ * Navigating from a web page (for example mozilla.org) to an internal page
+ * (like about:addons) might trigger a change of browser's remoteness.
+ * 'Remoteness change' means that rendering page content moves from child
+ * process into the parent process or the other way around.
+ * This test ensures that findbar properly handles such a change.
+ */
+add_task(async function test_reinitialization_at_remoteness_change() {
+  // This test only makes sence in e10s evironment.
+  if (!gMultiProcessBrowser) {
+    info("Skipping this test because of non-e10s environment.");
+    return;
+  }
+
+  info("Ensure findbar re-initialization at remoteness change.");
+
+  // Load a remote page and trigger findbar construction.
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+  let browser = gBrowser.getBrowserForTab(tab);
+  let findbar = await gBrowser.getFindBar();
+
+  // Findbar should operate normally.
+  await promiseFindFinished("z", false);
+  is(
+    findbar._findStatusDesc.textContent,
+    findbar._notFoundStr,
+    "Findbar status text should be 'Phrase not found'"
+  );
+
+  await promiseFindFinished("s", false);
+  ok(!findbar._findStatusDesc.textContent, "Findbar status should be empty");
+
+  // Moving browser into the parent process and reloading sample data.
+  ok(browser.isRemoteBrowser, "Browser should be remote now.");
+  await promiseRemotenessChange(tab, false);
+  let docLoaded = BrowserTestUtils.browserLoaded(
+    browser,
+    false,
+    E10S_PARENT_TEST_PAGE_URI
+  );
+  BrowserTestUtils.loadURI(browser, E10S_PARENT_TEST_PAGE_URI);
+  await docLoaded;
+  ok(!browser.isRemoteBrowser, "Browser should not be remote any more.");
+  browser.contentDocument.body.append("The letter s.");
+  browser.contentDocument.body.clientHeight; // Force flush.
+
+  // Findbar should keep operating normally after remoteness change.
+  await promiseFindFinished("z", false);
+  is(
+    findbar._findStatusDesc.textContent,
+    findbar._notFoundStr,
+    "Findbar status text should be 'Phrase not found'"
+  );
+
+  await promiseFindFinished("s", false);
+  ok(!findbar._findStatusDesc.textContent, "Findbar status should be empty");
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+/**
+ * Ensure that the initial typed characters aren't lost immediately after
+ * opening the find bar.
+ */
+add_task(async function e10sLostKeys() {
+  // This test only makes sence in e10s evironment.
+  if (!gMultiProcessBrowser) {
+    info("Skipping this test because of non-e10s environment.");
+    return;
+  }
+
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+
+  ok(!gFindBarInitialized, "findbar isn't initialized yet");
+
+  await gFindBarPromise;
+  let findBar = gFindBar;
+  let initialValue = findBar._findField.value;
+
+  await EventUtils.synthesizeAndWaitKey(
+    "F",
+    { accelKey: true },
+    window,
+    null,
+    () => {
+      // We can't afford to wait for the promise to resolve, by then the
+      // find bar is visible and focused, so sending characters to the
+      // content browser wouldn't work.
+      isnot(
+        document.activeElement,
+        findBar._findField,
+        "findbar is not yet focused"
+      );
+      EventUtils.synthesizeKey("a");
+      EventUtils.synthesizeKey("b");
+      EventUtils.synthesizeKey("c");
+      is(
+        findBar._findField.value,
+        initialValue,
+        "still has initial find query"
+      );
+    }
+  );
+
+  await BrowserTestUtils.waitForCondition(
+    () => findBar._findField.value.length == 3
+  );
+  is(document.activeElement, findBar._findField, "findbar is now focused");
+  is(findBar._findField.value, "abc", "abc fully entered as find query");
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+/**
+ * This test makes sure that keyboard operations still occur
+ * after the findbar is opened and closed.
+ */
+add_task(async function test_open_and_close_keys() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "data:text/html,<body style='height: 5000px;'>Hello There</body>"
+  );
+
+  await gFindBarPromise;
+  let findBar = gFindBar;
+
+  is(findBar.hidden, true, "Findbar is hidden now.");
+  let openedPromise = BrowserTestUtils.waitForEvent(findBar, "findbaropen");
+  await EventUtils.synthesizeKey("f", { accelKey: true });
+  await openedPromise;
+
+  is(findBar.hidden, false, "Findbar should not be hidden.");
+
+  let closedPromise = BrowserTestUtils.waitForEvent(findBar, "findbarclose");
+  await EventUtils.synthesizeKey("KEY_Escape");
+  await closedPromise;
+
+  let scrollPromise = BrowserTestUtils.waitForContentEvent(
+    tab.linkedBrowser,
+    "scroll"
+  );
+  await EventUtils.synthesizeKey("KEY_ArrowDown");
+  await scrollPromise;
+
+  let scrollPosition = await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [],
+    async function() {
+      return content.document.body.scrollTop;
+    }
+  );
+
+  ok(scrollPosition > 0, "Scrolled ok to " + scrollPosition);
+
+  BrowserTestUtils.removeTab(tab);
+});
+
+// This test loads an editable area within an iframe and then
+// performs a search. Focusing the editable area should still
+// allow keyboard events to be received.
+add_task(async function test_hotkey_insubframe() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI_WITHIFRAME
+  );
+
+  await gFindBarPromise;
+  let findBar = gFindBar;
+
+  // Focus the editable area within the frame.
+  let browser = gBrowser.selectedBrowser;
+  let frameBC = browser.browsingContext.children[0];
+  await SpecialPowers.spawn(frameBC, [], async () => {
+    content.document.body.focus();
+    content.document.defaultView.focus();
+  });
+
+  // Start a find and wait for the findbar to open.
+  let findBarOpenPromise = BrowserTestUtils.waitForEvent(
+    gBrowser,
+    "findbaropen"
+  );
+  EventUtils.synthesizeKey("f", { accelKey: true });
+  await findBarOpenPromise;
+
+  // Opening the findbar would have focused the find textbox.
+  // Focus the editable area again.
+  let cursorPos = await SpecialPowers.spawn(frameBC, [], async () => {
+    content.document.body.focus();
+    content.document.defaultView.focus();
+    return content.getSelection().anchorOffset;
+  });
+  is(cursorPos, 0, "initial cursor position");
+
+  // Try moving the caret.
+  await BrowserTestUtils.synthesizeKey("KEY_ArrowRight", {}, frameBC);
+
+  cursorPos = await SpecialPowers.spawn(frameBC, [], async () => {
+    return content.getSelection().anchorOffset;
+  });
+  is(cursorPos, 1, "cursor moved");
+
+  await closeFindbarAndWait(findBar);
+  gBrowser.removeTab(tab);
+});
+
+/**
+ * Reloading a page should use the same match case / whole word
+ * state for the search.
+ */
+add_task(async function test_preservestate_on_reload() {
+  for (let stateChange of ["case-sensitive", "entire-word"]) {
+    let tab = await BrowserTestUtils.openNewForegroundTab(
+      gBrowser,
+      "data:text/html,<p>There is a cat named Theo in the kitchen with another cat named Catherine. The two of them are thirsty."
+    );
+
+    // Start a find and wait for the findbar to open.
+    let findBarOpenPromise = BrowserTestUtils.waitForEvent(
+      gBrowser,
+      "findbaropen"
+    );
+    EventUtils.synthesizeKey("f", { accelKey: true });
+    await findBarOpenPromise;
+
+    let isEntireWord = stateChange == "entire-word";
+
+    let findbar = await gBrowser.getFindBar();
+
+    // Find some text.
+    let promiseMatches = promiseGetMatchCount(findbar);
+    await promiseFindFinished("The", true);
+
+    let matches = await promiseMatches;
+    is(matches.current, 1, "Correct match position " + stateChange);
+    is(matches.total, 7, "Correct number of matches " + stateChange);
+
+    // Turn on the case sensitive or entire word option.
+    findbar.getElement("find-" + stateChange).click();
+
+    promiseMatches = promiseGetMatchCount(findbar);
+    gFindBar.onFindAgainCommand();
+    matches = await promiseMatches;
+    is(
+      matches.current,
+      2,
+      "Correct match position after state change matches " + stateChange
+    );
+    is(
+      matches.total,
+      isEntireWord ? 2 : 3,
+      "Correct number after state change matches " + stateChange
+    );
+
+    // Reload the page.
+    let loadedPromise = BrowserTestUtils.browserLoaded(
+      gBrowser.selectedBrowser,
+      true
+    );
+    gBrowser.reload();
+    await loadedPromise;
+
+    // Perform a find again. The state should be preserved.
+    promiseMatches = promiseGetMatchCount(findbar);
+    gFindBar.onFindAgainCommand();
+    matches = await promiseMatches;
+    is(
+      matches.current,
+      1,
+      "Correct match position after reload and find again " + stateChange
+    );
+    is(
+      matches.total,
+      isEntireWord ? 2 : 3,
+      "Correct number of matches after reload and find again " + stateChange
+    );
+
+    // Turn off the case sensitive or entire word option and find again.
+    findbar.getElement("find-" + stateChange).click();
+
+    promiseMatches = promiseGetMatchCount(findbar);
+    gFindBar.onFindAgainCommand();
+    matches = await promiseMatches;
+
+    is(
+      matches.current,
+      isEntireWord ? 4 : 2,
+      "Correct match position after reload and find again reset " + stateChange
+    );
+    is(
+      matches.total,
+      7,
+      "Correct number of matches after reload and find again reset " +
+        stateChange
+    );
+
+    findbar.clear();
+    await closeFindbarAndWait(findbar);
+
+    gBrowser.removeTab(tab);
+  }
+});
+
+async function promiseFindFinished(searchText, highlightOn) {
+  let findbar = await gBrowser.getFindBar();
+  findbar.startFind(findbar.FIND_NORMAL);
+  let highlightElement = findbar.getElement("highlight");
+  if (highlightElement.checked != highlightOn) {
+    highlightElement.click();
+  }
+  return new Promise(resolve => {
+    executeSoon(() => {
+      findbar._findField.value = searchText;
+
+      let resultListener;
+      // When highlighting is on the finder sends a second "FOUND" message after
+      // the search wraps. This causes timing problems with e10s. waitMore
+      // forces foundOrTimeout wait for the second "FOUND" message before
+      // resolving the promise.
+      let waitMore = highlightOn;
+      let findTimeout = setTimeout(() => foundOrTimedout(null), 2000);
+      let foundOrTimedout = function(aData) {
+        if (aData !== null && waitMore) {
+          waitMore = false;
+          return;
+        }
+        if (aData === null) {
+          info("Result listener not called, timeout reached.");
+        }
+        clearTimeout(findTimeout);
+        findbar.browser.finder.removeResultListener(resultListener);
+        resolve();
+      };
+
+      resultListener = {
+        onFindResult: foundOrTimedout,
+        onCurrentSelection() {},
+        onMatchesCountResult() {},
+        onHighlightFinished() {},
+      };
+      findbar.browser.finder.addResultListener(resultListener);
+      findbar._find();
+    });
+  });
+}
+
+function promiseGetMatchCount(findbar) {
+  return new Promise(resolve => {
+    let resultListener = {
+      onFindResult() {},
+      onCurrentSelection() {},
+      onHighlightFinished() {},
+      onMatchesCountResult(response) {
+        if (response.total > 0) {
+          findbar.browser.finder.removeResultListener(resultListener);
+          resolve(response);
+        }
+      },
+    };
+    findbar.browser.finder.addResultListener(resultListener);
+  });
+}
+
+function promiseRemotenessChange(tab, shouldBeRemote) {
+  return new Promise(resolve => {
+    let browser = gBrowser.getBrowserForTab(tab);
+    tab.addEventListener(
+      "TabRemotenessChange",
+      function() {
+        resolve();
+      },
+      { once: true }
+    );
+    let remoteType = shouldBeRemote
+      ? E10SUtils.DEFAULT_REMOTE_TYPE
+      : E10SUtils.NOT_REMOTE;
+    gBrowser.updateBrowserRemoteness(browser, { remoteType });
+  });
+}
diff --git a/toolkit/content/tests/browser/browser_findbar_disabled_manual.js b/toolkit/content/tests/browser/browser_findbar_disabled_manual.js
new file mode 100644
index 0000000000..ef37f7dc9a
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_findbar_disabled_manual.js
@@ -0,0 +1,33 @@
+const TEST_PAGE_URI = "data:text/html;charset=utf-8,The letter s.";
+
+// Disable manual (FAYT) findbar hotkeys.
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["accessibility.typeaheadfind.manual", false]],
+  });
+});
+
+// Makes sure that the findbar hotkeys (' and /) have no effect.
+add_task(async function test_hotkey_disabled() {
+  // Opening new tab.
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    TEST_PAGE_URI
+  );
+  let browser = gBrowser.getBrowserForTab(tab);
+  let findbar = await gBrowser.getFindBar();
+
+  // Pressing these keys open the findbar normally.
+  const HOTKEYS = ["/", "'"];
+
+  // Make sure no findbar appears when pressed.
+  for (let key of HOTKEYS) {
+    is(findbar.hidden, true, "Findbar is hidden now.");
+    gBrowser.selectedTab = tab;
+    await SimpleTest.promiseFocus(gBrowser.selectedBrowser);
+    await BrowserTestUtils.sendChar(key, browser);
+    is(findbar.hidden, true, "Findbar should still be hidden.");
+  }
+
+  gBrowser.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_isSynthetic.js b/toolkit/content/tests/browser/browser_isSynthetic.js
new file mode 100644
index 0000000000..f2207cb2b6
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_isSynthetic.js
@@ -0,0 +1,66 @@
+function LocationChangeListener(browser) {
+  this.browser = browser;
+  browser.addProgressListener(this, Ci.nsIWebProgress.NOTIFY_LOCATION);
+}
+
+LocationChangeListener.prototype = {
+  wasSynthetic: false,
+  browser: null,
+
+  destroy() {
+    this.browser.removeProgressListener(this);
+  },
+
+  onLocationChange(webProgress, request, location, flags) {
+    this.wasSynthetic = this.browser.isSyntheticDocument;
+  },
+
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIWebProgressListener",
+    "nsISupportsWeakReference",
+  ]),
+};
+
+const FILES = gTestPath
+  .replace("browser_isSynthetic.js", "")
+  .replace("chrome://mochitests/content/", "http://example.com/");
+
+function waitForPageShow(browser) {
+  return BrowserTestUtils.waitForContentEvent(browser, "pageshow", true);
+}
+
+add_task(async function() {
+  let tab = BrowserTestUtils.addTab(gBrowser, "about:blank");
+  let browser = tab.linkedBrowser;
+  await BrowserTestUtils.browserLoaded(browser);
+  let listener = new LocationChangeListener(browser);
+
+  is(browser.isSyntheticDocument, false, "Should not be synthetic");
+
+  let loadPromise = waitForPageShow(browser);
+  BrowserTestUtils.loadURI(browser, "data:text/html;charset=utf-8,<html/>");
+  await loadPromise;
+  is(listener.wasSynthetic, false, "Should not be synthetic");
+  is(browser.isSyntheticDocument, false, "Should not be synthetic");
+
+  loadPromise = waitForPageShow(browser);
+  BrowserTestUtils.loadURI(browser, FILES + "empty.png");
+  await loadPromise;
+  is(listener.wasSynthetic, true, "Should be synthetic");
+  is(browser.isSyntheticDocument, true, "Should be synthetic");
+
+  loadPromise = waitForPageShow(browser);
+  browser.goBack();
+  await loadPromise;
+  is(listener.wasSynthetic, false, "Should not be synthetic");
+  is(browser.isSyntheticDocument, false, "Should not be synthetic");
+
+  loadPromise = waitForPageShow(browser);
+  browser.goForward();
+  await loadPromise;
+  is(listener.wasSynthetic, true, "Should be synthetic");
+  is(browser.isSyntheticDocument, true, "Should be synthetic");
+
+  listener.destroy();
+  gBrowser.removeTab(tab);
+});
diff --git a/toolkit/content/tests/browser/browser_keyevents_during_autoscrolling.js b/toolkit/content/tests/browser/browser_keyevents_during_autoscrolling.js
new file mode 100644
index 0000000000..4eda24f531
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_keyevents_during_autoscrolling.js
@@ -0,0 +1,129 @@
+add_task(async function() {
+  const kPrefName_AutoScroll = "general.autoScroll";
+  Services.prefs.setBoolPref(kPrefName_AutoScroll, true);
+  registerCleanupFunction(() =>
+    Services.prefs.clearUserPref(kPrefName_AutoScroll)
+  );
+
+  const kNoKeyEvents = 0;
+  const kKeyDownEvent = 1;
+  const kKeyPressEvent = 2;
+  const kKeyUpEvent = 4;
+  const kAllKeyEvents = 7;
+
+  var expectedKeyEvents;
+  var dispatchedKeyEvents;
+  var key;
+
+  /**
+   * Encapsulates EventUtils.sendChar().
+   */
+  function sendChar(aChar) {
+    key = aChar;
+    dispatchedKeyEvents = kNoKeyEvents;
+    EventUtils.sendChar(key);
+    is(
+      dispatchedKeyEvents,
+      expectedKeyEvents,
+      "unexpected key events were dispatched or not dispatched: " + key
+    );
+  }
+
+  /**
+   * Encapsulates EventUtils.sendKey().
+   */
+  function sendKey(aKey) {
+    key = aKey;
+    dispatchedKeyEvents = kNoKeyEvents;
+    EventUtils.sendKey(key);
+    is(
+      dispatchedKeyEvents,
+      expectedKeyEvents,
+      "unexpected key events were dispatched or not dispatched: " + key
+    );
+  }
+
+  function onKey(aEvent) {
+    //    if (aEvent.target != root && aEvent.target != root.ownerDocument.body) {
+    //      ok(false, "unknown target: " + aEvent.target.tagName);
+    //      return;
+    //    }
+
+    var keyFlag;
+    switch (aEvent.type) {
+      case "keydown":
+        keyFlag = kKeyDownEvent;
+        break;
+      case "keypress":
+        keyFlag = kKeyPressEvent;
+        break;
+      case "keyup":
+        keyFlag = kKeyUpEvent;
+        break;
+      default:
+        ok(false, "Unknown events: " + aEvent.type);
+        return;
+    }
+    dispatchedKeyEvents |= keyFlag;
+    is(keyFlag, expectedKeyEvents & keyFlag, aEvent.type + " fired: " + key);
+  }
+
+  var dataUri = 'data:text/html,<body style="height:10000px;"></body>';
+
+  await BrowserTestUtils.withNewTab(dataUri, async function(browser) {
+    info("Loaded data URI in new tab");
+    await SimpleTest.promiseFocus(browser);
+    info("Focused selected browser");
+
+    window.addEventListener("keydown", onKey);
+    window.addEventListener("keypress", onKey);
+    window.addEventListener("keyup", onKey);
+    registerCleanupFunction(() => {
+      window.removeEventListener("keydown", onKey);
+      window.removeEventListener("keypress", onKey);
+      window.removeEventListener("keyup", onKey);
+    });
+
+    // Test whether the key events are handled correctly under normal condition
+    expectedKeyEvents = kAllKeyEvents;
+    sendChar("A");
+
+    // Start autoscrolling by middle button click on the page
+    info("Creating popup shown promise");
+    let shownPromise = BrowserTestUtils.waitForEvent(
+      window,
+      "popupshown",
+      false,
+      event => event.originalTarget.className == "autoscroller"
+    );
+    await BrowserTestUtils.synthesizeMouseAtPoint(
+      10,
+      10,
+      { button: 1 },
+      gBrowser.selectedBrowser
+    );
+    info("Waiting for autoscroll popup to show");
+    await shownPromise;
+
+    // Most key events should be eaten by the browser.
+    expectedKeyEvents = kNoKeyEvents;
+    sendChar("A");
+    sendKey("DOWN");
+    sendKey("RETURN");
+    sendKey("RETURN");
+    sendKey("HOME");
+    sendKey("END");
+    sendKey("TAB");
+    sendKey("RETURN");
+
+    // Finish autoscrolling by ESC key.  Note that only keydown and keypress
+    // events are eaten because keyup event is fired *after* the autoscrolling
+    // is finished.
+    expectedKeyEvents = kKeyUpEvent;
+    sendKey("ESCAPE");
+
+    // Test whether the key events are handled correctly under normal condition
+    expectedKeyEvents = kAllKeyEvents;
+    sendChar("A");
+  });
+});
diff --git a/toolkit/content/tests/browser/browser_label_textlink.js b/toolkit/content/tests/browser/browser_label_textlink.js
new file mode 100644
index 0000000000..e6b967cbe9
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_label_textlink.js
@@ -0,0 +1,63 @@
+add_task(async function() {
+  await BrowserTestUtils.withNewTab(
+    { gBrowser, url: "about:preferences" },
+    async function(browser) {
+      let newTabURL = "http://www.example.com/";
+      await SpecialPowers.spawn(browser, [newTabURL], async function(
+        newTabURL
+      ) {
+        let doc = content.document;
+        let label = doc.createXULElement("label", { is: "text-link" });
+        label.href = newTabURL;
+        label.id = "textlink-test";
+        label.textContent = "click me";
+        doc.body.append(label);
+      });
+
+      // Test that click will open tab in foreground.
+      let awaitNewTab = BrowserTestUtils.waitForNewTab(gBrowser, newTabURL);
+      await BrowserTestUtils.synthesizeMouseAtCenter(
+        "#textlink-test",
+        {},
+        browser
+      );
+      let newTab = await awaitNewTab;
+      is(
+        newTab.linkedBrowser,
+        gBrowser.selectedBrowser,
+        "selected tab should be example page"
+      );
+      BrowserTestUtils.removeTab(gBrowser.selectedTab);
+
+      // Test that ctrl+shift+click/meta+shift+click will open tab in background.
+      awaitNewTab = BrowserTestUtils.waitForNewTab(gBrowser, newTabURL);
+      await BrowserTestUtils.synthesizeMouseAtCenter(
+        "#textlink-test",
+        { ctrlKey: true, metaKey: true, shiftKey: true },
+        browser
+      );
+      await awaitNewTab;
+      is(
+        gBrowser.selectedBrowser,
+        browser,
+        "selected tab should be original tab"
+      );
+      BrowserTestUtils.removeTab(gBrowser.tabs[gBrowser.tabs.length - 1]);
+
+      // Middle-clicking should open tab in foreground.
+      awaitNewTab = BrowserTestUtils.waitForNewTab(gBrowser, newTabURL);
+      await BrowserTestUtils.synthesizeMouseAtCenter(
+        "#textlink-test",
+        { button: 1 },
+        browser
+      );
+      newTab = await awaitNewTab;
+      is(
+        newTab.linkedBrowser,
+        gBrowser.selectedBrowser,
+        "selected tab should be example page"
+      );
+      BrowserTestUtils.removeTab(gBrowser.tabs[gBrowser.tabs.length - 1]);
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_license_links.js b/toolkit/content/tests/browser/browser_license_links.js
new file mode 100644
index 0000000000..3eff69ba75
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_license_links.js
@@ -0,0 +1,27 @@
+/* Any copyright is dedicated to the Public Domain.
+ * https://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Verify that we can reach about:rights and about:buildconfig using links
+ * from about:license.
+ */
+add_task(async function check_links() {
+  await BrowserTestUtils.withNewTab("about:license", async browser => {
+    for (let otherPage of ["about:rights", "about:buildconfig"]) {
+      let tabPromise = BrowserTestUtils.waitForNewTab(gBrowser, otherPage);
+      await BrowserTestUtils.synthesizeMouse(
+        `a[href='${otherPage}']`,
+        2,
+        2,
+        { accelKey: true },
+        browser
+      );
+      info("Clicked " + otherPage + " link");
+      let tab = await tabPromise;
+      ok(true, otherPage + " tab opened correctly");
+      BrowserTestUtils.removeTab(tab);
+    }
+  });
+});
diff --git a/toolkit/content/tests/browser/browser_mediaStreamPlayback.html b/toolkit/content/tests/browser/browser_mediaStreamPlayback.html
new file mode 100644
index 0000000000..09685d488e
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_mediaStreamPlayback.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+<body>
+<video id="v" controls></video>
+<script>
+const v = document.getElementById("v");
+
+function audioTrack() {
+  const ctx = new AudioContext(), oscillator = ctx.createOscillator();
+  const dst = oscillator.connect(ctx.createMediaStreamDestination());
+  oscillator.start();
+  return dst.stream.getAudioTracks()[0];
+}
+
+function videoTrack(width = 640, height = 480) {
+  const canvas = Object.assign(document.createElement("canvas"), {width, height});
+  canvas.getContext('2d').fillRect(0, 0, width, height);
+  return canvas.captureStream(10).getVideoTracks()[0];
+}
+
+onload = () => v.srcObject = new MediaStream([videoTrack(), audioTrack()]);
+</script>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/browser_mediaStreamPlaybackWithoutAudio.html b/toolkit/content/tests/browser/browser_mediaStreamPlaybackWithoutAudio.html
new file mode 100644
index 0000000000..fbc9fcb033
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_mediaStreamPlaybackWithoutAudio.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+<body>
+<video id="v" controls></video>
+<script>
+const v = document.getElementById("v");
+
+function videoTrack(width = 640, height = 480) {
+  const canvas = Object.assign(document.createElement("canvas"), {width, height});
+  canvas.getContext('2d').fillRect(0, 0, width, height);
+  return canvas.captureStream(10).getVideoTracks()[0];
+}
+
+onload = () => v.srcObject = new MediaStream([videoTrack()]);
+</script>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/browser_media_wakelock.js b/toolkit/content/tests/browser/browser_media_wakelock.js
new file mode 100644
index 0000000000..dee4b1a26f
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_media_wakelock.js
@@ -0,0 +1,160 @@
+/**
+ * Test whether the wakelock state is correct under different situations. However,
+ * the lock state of power manager doesn't equal to the actual platform lock.
+ * Now we don't have any way to detect whether platform lock is set correctly or
+ * not, but we can at least make sure the specific topic's state in power manager
+ * is correct.
+ */
+"use strict";
+
+// Import this in order to use `triggerPictureInPicture()`.
+/* import-globals-from ../../../../toolkit/components/pictureinpicture/tests/head.js */
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/toolkit/components/pictureinpicture/tests/head.js",
+  this
+);
+
+const LOCATION = "https://example.com/browser/toolkit/content/tests/browser/";
+const AUDIO_WAKELOCK_NAME = "audio-playing";
+const VIDEO_WAKELOCK_NAME = "video-playing";
+
+add_task(async function testCheckWakelockWhenChangeTabVisibility() {
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing video",
+    url: "file_video.html",
+    lockAudio: true,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing muted video",
+    url: "file_video.html",
+    additionalParams: {
+      muted: true,
+    },
+    lockAudio: false,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing volume=0 video",
+    url: "file_video.html",
+    additionalParams: {
+      volume: 0.0,
+    },
+    lockAudio: false,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing video without audio in it",
+    url: "file_videoWithoutAudioTrack.html",
+    lockAudio: false,
+    lockVideo: false,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing audio in video element",
+    url: "file_videoWithAudioOnly.html",
+    lockAudio: true,
+    lockVideo: false,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing audio in audio element",
+    url: "file_mediaPlayback2.html",
+    lockAudio: true,
+    lockVideo: false,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing video from media stream with audio and video tracks",
+    url: "browser_mediaStreamPlayback.html",
+    lockAudio: true,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing video from media stream without audio track",
+    url: "browser_mediaStreamPlaybackWithoutAudio.html",
+    lockAudio: true,
+    lockVideo: true,
+  });
+});
+
+/**
+ * Following are helper functions.
+ */
+async function checkWakelockWhenChangeTabVisibility({
+  description,
+  url,
+  additionalParams,
+  lockAudio,
+  lockVideo,
+}) {
+  const originalTab = gBrowser.selectedTab;
+  info(`start a new tab for '${description}'`);
+  const mediaTab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    LOCATION + url
+  );
+
+  info(`wait for media starting playing`);
+  await waitUntilVideoStarted(mediaTab, additionalParams);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(`switch media tab to background`);
+  await BrowserTestUtils.switchTab(window.gBrowser, originalTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: false,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: false,
+  });
+
+  info(`switch media tab to foreground again`);
+  await BrowserTestUtils.switchTab(window.gBrowser, mediaTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(`remove tab`);
+  if (mediaTab.PIPWindow) {
+    await BrowserTestUtils.closeWindow(mediaTab.PIPWindow);
+  }
+  BrowserTestUtils.removeTab(mediaTab);
+}
+
+async function waitUntilVideoStarted(tab, { muted, volume } = {}) {
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [muted, volume],
+    async (muted, volume) => {
+      const video = content.document.getElementById("v");
+      if (!video) {
+        ok(false, "can't get media element!");
+        return;
+      }
+      if (muted) {
+        video.muted = muted;
+      }
+      if (volume !== undefined) {
+        video.volume = volume;
+      }
+      ok(
+        await video.play().then(
+          () => true,
+          () => false
+        ),
+        `video started playing.`
+      );
+    }
+  );
+}
diff --git a/toolkit/content/tests/browser/browser_media_wakelock_PIP.js b/toolkit/content/tests/browser/browser_media_wakelock_PIP.js
new file mode 100644
index 0000000000..d75c1ef1d7
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_media_wakelock_PIP.js
@@ -0,0 +1,156 @@
+/**
+ * Test the wakelock usage for video being used in the picture-in-picuture (PIP)
+ * mode. When video is playing in PIP window, we would always request a video
+ * wakelock, and request audio wakelock only when video is audible.
+ */
+add_task(async function testCheckWakelockForPIPVideo() {
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing a PIP video",
+    lockAudio: true,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing a muted PIP video",
+    additionalParams: {
+      muted: true,
+    },
+    lockAudio: false,
+    lockVideo: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing a volume=0 PIP video",
+    additionalParams: {
+      volume: 0.0,
+    },
+    lockAudio: false,
+    lockVideo: true,
+  });
+});
+
+/**
+ * Following are helper functions and variables.
+ */
+const PAGE_URL =
+  "https://example.com/browser/toolkit/content/tests/browser/file_video.html";
+const AUDIO_WAKELOCK_NAME = "audio-playing";
+const VIDEO_WAKELOCK_NAME = "video-playing";
+const TEST_VIDEO_ID = "v";
+
+// Import this in order to use `triggerPictureInPicture()`.
+/* import-globals-from ../../../../toolkit/components/pictureinpicture/tests/head.js */
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/toolkit/components/pictureinpicture/tests/head.js",
+  this
+);
+
+async function checkWakelockWhenChangeTabVisibility({
+  description,
+  additionalParams,
+  lockAudio,
+  lockVideo,
+}) {
+  const originalTab = gBrowser.selectedTab;
+  info(`start a new tab for '${description}'`);
+  const tab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    PAGE_URL
+  );
+
+  info(`wait for PIP video starting playing`);
+  await startPIPVideo(tab, additionalParams);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(
+    `switch tab to background and still own foreground locks due to visible PIP video`
+  );
+  await BrowserTestUtils.switchTab(window.gBrowser, originalTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(`pausing PIP video should release all locks`);
+  await pausePIPVideo(tab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: false,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: false,
+  });
+
+  info(`resuming PIP video should request locks again`);
+  await resumePIPVideo(tab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(`switch tab to foreground again`);
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock: lockAudio,
+    isForegroundLock: true,
+  });
+  await waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, {
+    needLock: lockVideo,
+    isForegroundLock: true,
+  });
+
+  info(`remove tab`);
+  await BrowserTestUtils.closeWindow(tab.PIPWindow);
+  BrowserTestUtils.removeTab(tab);
+}
+
+async function startPIPVideo(tab, { muted, volume } = {}) {
+  tab.PIPWindow = await triggerPictureInPicture(
+    tab.linkedBrowser,
+    TEST_VIDEO_ID
+  );
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [muted, volume, TEST_VIDEO_ID],
+    async (muted, volume, Id) => {
+      const video = content.document.getElementById(Id);
+      if (muted) {
+        video.muted = muted;
+      }
+      if (volume !== undefined) {
+        video.volume = volume;
+      }
+      ok(
+        await video.play().then(
+          () => true,
+          () => false
+        ),
+        `video started playing.`
+      );
+    }
+  );
+}
+
+function pausePIPVideo(tab) {
+  return SpecialPowers.spawn(tab.linkedBrowser, [TEST_VIDEO_ID], Id => {
+    content.document.getElementById(Id).pause();
+  });
+}
+
+function resumePIPVideo(tab) {
+  return SpecialPowers.spawn(tab.linkedBrowser, [TEST_VIDEO_ID], async Id => {
+    await content.document.getElementById(Id).play();
+  });
+}
diff --git a/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js b/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js
new file mode 100644
index 0000000000..7c40b5fe1a
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_media_wakelock_webaudio.js
@@ -0,0 +1,127 @@
+/**
+ * Test if wakelock can be required correctly when we play web audio. The
+ * wakelock should only be required when web audio is audible.
+ */
+
+const AUDIO_WAKELOCK_NAME = "audio-playing";
+const VIDEO_WAKELOCK_NAME = "video-playing";
+
+add_task(async function testCheckAudioWakelockWhenChangeTabVisibility() {
+  await checkWakelockWhenChangeTabVisibility({
+    description: "playing audible web audio",
+    needLock: true,
+  });
+  await checkWakelockWhenChangeTabVisibility({
+    description: "suspended web audio",
+    additionalParams: {
+      suspend: true,
+    },
+    needLock: false,
+  });
+});
+
+add_task(
+  async function testBrieflyAudibleAudioContextReleasesAudioWakeLockWhenInaudible() {
+    const tab = await BrowserTestUtils.openNewForegroundTab(
+      window.gBrowser,
+      "about:blank"
+    );
+
+    info(`make a short noise on web audio`);
+    await Promise.all([
+      // As the sound would only happen for a really short period, calling
+      // checking wakelock first helps to ensure that we won't miss that moment.
+      waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+        needLock: true,
+        isForegroundLock: true,
+      }),
+      createWebAudioDocument(tab, { stopTimeOffset: 0.1 }),
+    ]);
+    await ensureNeverAcquireVideoWakelock();
+
+    info(`audio wakelock should be released after web audio becomes silent`);
+    await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, false, {
+      needLock: false,
+    });
+    await ensureNeverAcquireVideoWakelock();
+
+    await BrowserTestUtils.removeTab(tab);
+  }
+);
+
+/**
+ * Following are helper functions.
+ */
+async function checkWakelockWhenChangeTabVisibility({
+  description,
+  additionalParams,
+  needLock,
+  elementIdForEnteringPIPMode,
+}) {
+  const originalTab = gBrowser.selectedTab;
+  info(`start a new tab for '${description}'`);
+  const mediaTab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    "about:blank"
+  );
+  await createWebAudioDocument(mediaTab, additionalParams);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: true,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`switch media tab to background`);
+  await BrowserTestUtils.switchTab(window.gBrowser, originalTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: false,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`switch media tab to foreground again`);
+  await BrowserTestUtils.switchTab(window.gBrowser, mediaTab);
+  await waitForExpectedWakeLockState(AUDIO_WAKELOCK_NAME, {
+    needLock,
+    isForegroundLock: true,
+  });
+  await ensureNeverAcquireVideoWakelock();
+
+  info(`remove media tab`);
+  BrowserTestUtils.removeTab(mediaTab);
+}
+
+function createWebAudioDocument(tab, { stopTimeOffset, suspend } = {}) {
+  return SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [suspend, stopTimeOffset],
+    async (suspend, stopTimeOffset) => {
+      // Create an oscillatorNode to produce sound.
+      content.ac = new content.AudioContext();
+      const ac = content.ac;
+      const dest = ac.destination;
+      const source = new content.OscillatorNode(ac);
+      source.start(ac.currentTime);
+      source.connect(dest);
+
+      if (stopTimeOffset) {
+        source.stop(ac.currentTime + 0.1);
+      }
+
+      if (suspend) {
+        await content.ac.suspend();
+      } else {
+        while (ac.state != "running") {
+          info(`wait until AudioContext starts running`);
+          await new Promise(r => (ac.onstatechange = r));
+        }
+        info("AudioContext is running");
+      }
+    }
+  );
+}
+
+function ensureNeverAcquireVideoWakelock() {
+  // Web audio won't play any video, we never need video wakelock.
+  return waitForExpectedWakeLockState(VIDEO_WAKELOCK_NAME, { needLock: false });
+}
diff --git a/toolkit/content/tests/browser/browser_quickfind_editable.js b/toolkit/content/tests/browser/browser_quickfind_editable.js
new file mode 100644
index 0000000000..7ece285602
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_quickfind_editable.js
@@ -0,0 +1,59 @@
+const PAGE =
+  "data:text/html,<div contenteditable>foo</div><input><textarea></textarea>";
+const DESIGNMODE_PAGE =
+  "data:text/html,<body onload='document.designMode=\"on\";'>";
+const HOTKEYS = ["/", "'"];
+
+async function test_hotkeys(browser, expected) {
+  let findbar = await gBrowser.getFindBar();
+  for (let key of HOTKEYS) {
+    is(findbar.hidden, true, "findbar is hidden");
+    await BrowserTestUtils.sendChar(key, gBrowser.selectedBrowser);
+    is(
+      findbar.hidden,
+      expected,
+      "findbar should" + (expected ? "" : " not") + " be hidden"
+    );
+    if (!expected) {
+      await closeFindbarAndWait(findbar);
+    }
+  }
+}
+
+async function focus_element(browser, query) {
+  await SpecialPowers.spawn(browser, [query], async function focus(query) {
+    let element = content.document.querySelector(query);
+    element.focus();
+  });
+}
+
+add_task(async function test_hotkey_on_editable_element() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: PAGE,
+    },
+    async function do_tests(browser) {
+      await test_hotkeys(browser, false);
+      const ELEMENTS = ["div", "input", "textarea"];
+      for (let elem of ELEMENTS) {
+        await focus_element(browser, elem);
+        await test_hotkeys(browser, true);
+        await focus_element(browser, ":root");
+        await test_hotkeys(browser, false);
+      }
+    }
+  );
+});
+
+add_task(async function test_hotkey_on_designMode_document() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: DESIGNMODE_PAGE,
+    },
+    async function do_tests(browser) {
+      await test_hotkeys(browser, true);
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_remoteness_change_listeners.js b/toolkit/content/tests/browser/browser_remoteness_change_listeners.js
new file mode 100644
index 0000000000..34c3c4112e
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_remoteness_change_listeners.js
@@ -0,0 +1,39 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Check that adding progress listeners to a browser doesn't break things
+ * when switching the remoteness of that browser.
+ */
+add_task(async function test_remoteness_switch_listeners() {
+  await BrowserTestUtils.withNewTab("about:support", async function(browser) {
+    let wpl;
+    let navigated = new Promise(resolve => {
+      wpl = {
+        onLocationChange() {
+          is(browser.currentURI.spec, "https://example.com/");
+          if (browser.currentURI?.spec == "https://example.com/") {
+            resolve();
+          }
+        },
+        QueryInterface: ChromeUtils.generateQI([
+          Ci.nsISupportsWeakReference,
+          Ci.nsIWebProgressListener2,
+          Ci.nsIWebProgressListener,
+        ]),
+      };
+      browser.addProgressListener(wpl);
+    });
+
+    let loaded = BrowserTestUtils.browserLoaded(
+      browser,
+      null,
+      "https://example.com/"
+    );
+    BrowserTestUtils.loadURI(browser, "https://example.com/");
+    await Promise.all([loaded, navigated]);
+    browser.removeProgressListener(wpl);
+  });
+});
diff --git a/toolkit/content/tests/browser/browser_resume_bkg_video_on_tab_hover.js b/toolkit/content/tests/browser/browser_resume_bkg_video_on_tab_hover.js
new file mode 100644
index 0000000000..f8087f6a60
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_resume_bkg_video_on_tab_hover.js
@@ -0,0 +1,154 @@
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_silentAudioTrack.html";
+
+async function check_video_decoding_state(args) {
+  let video = content.document.getElementById("autoplay");
+  if (!video) {
+    ok(false, "Can't get the video element!");
+  }
+
+  let isSuspended = args.suspend;
+  let reload = args.reload;
+
+  if (reload) {
+    // It is too late to register event handlers when playback is half
+    // way done. Let's start playback from the beginning so we won't
+    // miss any events.
+    video.load();
+    video.play();
+  }
+
+  let state = isSuspended ? "suspended" : "resumed";
+  let event = isSuspended ? "mozentervideosuspend" : "mozexitvideosuspend";
+  return new Promise(resolve => {
+    video.addEventListener(
+      event,
+      function() {
+        ok(true, `Video decoding is ${state}.`);
+        resolve();
+      },
+      { once: true }
+    );
+  });
+}
+
+async function check_should_send_unselected_tab_hover_msg(browser) {
+  info("did not update the value now, wait until it changes.");
+  if (browser.shouldHandleUnselectedTabHover) {
+    ok(
+      true,
+      "Should send unselected tab hover msg, someone is listening for it."
+    );
+    return true;
+  }
+  return BrowserTestUtils.waitForCondition(
+    () => browser.shouldHandleUnselectedTabHover,
+    "Should send unselected tab hover msg, someone is listening for it."
+  );
+}
+
+async function check_should_not_send_unselected_tab_hover_msg(browser) {
+  info("did not update the value now, wait until it changes.");
+  return BrowserTestUtils.waitForCondition(
+    () => !browser.shouldHandleUnselectedTabHover,
+    "Should not send unselected tab hover msg, no one is listening for it."
+  );
+}
+
+function get_video_decoding_suspend_promise(browser, reload) {
+  let suspend = true;
+  return SpecialPowers.spawn(
+    browser,
+    [{ suspend, reload }],
+    check_video_decoding_state
+  );
+}
+
+function get_video_decoding_resume_promise(browser) {
+  let suspend = false;
+  let reload = false;
+  return ContentTask.spawn(
+    browser,
+    { suspend, reload },
+    check_video_decoding_state
+  );
+}
+
+/**
+ * Because of bug1029451, we can't receive "mouseover" event correctly when
+ * we disable non-test mouse event. Therefore, we can't synthesize mouse event
+ * to simulate cursor hovering, so we temporarily use a hacky way to resume and
+ * suspend video decoding.
+ */
+function cursor_hover_over_tab_and_resume_video_decoding(browser) {
+  // TODO : simulate cursor hovering over the tab after fixing bug1029451.
+  browser.unselectedTabHover(true /* hover */);
+}
+
+function cursor_leave_tab_and_suspend_video_decoding(browser) {
+  // TODO : simulate cursor leaveing the tab after fixing bug1029451.
+  browser.unselectedTabHover(false /* leave */);
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.block-autoplay-until-in-foreground", false],
+      ["media.suspend-bkgnd-video.enabled", true],
+      ["media.suspend-bkgnd-video.delay-ms", 0],
+      ["media.resume-bkgnd-video-on-tabhover", true],
+    ],
+  });
+});
+
+/**
+ * TODO : add the following user-level tests after fixing bug1029451.
+ * test1 - only affect the unselected tab
+ * test2 - only affect the tab with suspended video
+ */
+add_task(async function resume_and_suspend_background_video_decoding() {
+  info("- open new background tab -");
+  let tab = BrowserTestUtils.addTab(window.gBrowser, "about:blank");
+  let browser = tab.linkedBrowser;
+  await BrowserTestUtils.browserLoaded(browser);
+
+  info("- before loading media, we shoudn't send the tab hover msg for tab -");
+  await check_should_not_send_unselected_tab_hover_msg(browser);
+  BrowserTestUtils.loadURI(browser, PAGE);
+  await BrowserTestUtils.browserLoaded(browser);
+
+  info("- should suspend background video decoding -");
+  await get_video_decoding_suspend_promise(browser, true);
+  await check_should_send_unselected_tab_hover_msg(browser);
+
+  info("- when cursor is hovering over the tab, resuming the video decoding -");
+  let promise = get_video_decoding_resume_promise(browser);
+  await cursor_hover_over_tab_and_resume_video_decoding(browser);
+  await promise;
+  await check_should_send_unselected_tab_hover_msg(browser);
+
+  info("- when cursor leaves the tab, suspending the video decoding -");
+  promise = get_video_decoding_suspend_promise(browser);
+  await cursor_leave_tab_and_suspend_video_decoding(browser);
+  await promise;
+  await check_should_send_unselected_tab_hover_msg(browser);
+
+  info("- select video's owner tab as foreground tab, should resume video -");
+  promise = get_video_decoding_resume_promise(browser);
+  await BrowserTestUtils.switchTab(window.gBrowser, tab);
+  await promise;
+  await check_should_send_unselected_tab_hover_msg(browser);
+
+  info("- video's owner tab goes to background again, should suspend video -");
+  promise = get_video_decoding_suspend_promise(browser);
+  let blankTab = await BrowserTestUtils.openNewForegroundTab(
+    window.gBrowser,
+    "about:blank"
+  );
+  await promise;
+  await check_should_send_unselected_tab_hover_msg(browser);
+
+  info("- remove tabs -");
+  BrowserTestUtils.removeTab(tab);
+  BrowserTestUtils.removeTab(blankTab);
+});
diff --git a/toolkit/content/tests/browser/browser_saveImageURL.js b/toolkit/content/tests/browser/browser_saveImageURL.js
new file mode 100644
index 0000000000..764e7e9aa5
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_saveImageURL.js
@@ -0,0 +1,75 @@
+"use strict";
+
+const IMAGE_PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/image_page.html";
+
+var MockFilePicker = SpecialPowers.MockFilePicker;
+
+MockFilePicker.init(window);
+MockFilePicker.returnValue = MockFilePicker.returnCancel;
+
+registerCleanupFunction(function() {
+  MockFilePicker.cleanup();
+});
+
+function waitForFilePicker() {
+  return new Promise(resolve => {
+    MockFilePicker.showCallback = () => {
+      MockFilePicker.showCallback = null;
+      ok(true, "Saw the file picker");
+      resolve();
+    };
+  });
+}
+
+/**
+ * Test that internalSave works when saving an image like the context menu does.
+ */
+add_task(async function preferred_API() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: IMAGE_PAGE,
+    },
+    async function(browser) {
+      let url = await SpecialPowers.spawn(browser, [], async function() {
+        let image = content.document.getElementById("image");
+        return image.href;
+      });
+
+      let filePickerPromise = waitForFilePicker();
+      internalSave(
+        url,
+        null, // document
+        "image.jpg",
+        null, // content disposition
+        "image/jpeg",
+        true, // bypass cache
+        null, // dialog title key
+        null, // chosen data
+        null, // no referrer info
+        null, // no document
+        false, // don't skip the filename prompt
+        null, // cache key
+        false, // not private.
+        gBrowser.contentPrincipal
+      );
+      await SpecialPowers.spawn(gBrowser.selectedBrowser, [], async () => {
+        let channel = docShell.currentDocumentChannel;
+        if (channel) {
+          todo(
+            channel.QueryInterface(Ci.nsIHttpChannelInternal)
+              .channelIsForDownload
+          );
+
+          // Throttleable is the only class flag assigned to downloads.
+          todo(
+            channel.QueryInterface(Ci.nsIClassOfService).classFlags ==
+              Ci.nsIClassOfService.Throttleable
+          );
+        }
+      });
+      await filePickerPromise;
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/browser_save_resend_postdata.js b/toolkit/content/tests/browser/browser_save_resend_postdata.js
new file mode 100644
index 0000000000..c519c19880
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_save_resend_postdata.js
@@ -0,0 +1,169 @@
+/* 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/. */
+
+var MockFilePicker = SpecialPowers.MockFilePicker;
+MockFilePicker.init(window);
+
+/**
+ * Test for bug 471962 <https://bugzilla.mozilla.org/show_bug.cgi?id=471962>:
+ * When saving an inner frame as file only, the POST data of the outer page is
+ * sent to the address of the inner page.
+ *
+ * Test for bug 485196 <https://bugzilla.mozilla.org/show_bug.cgi?id=485196>:
+ * Web page generated by POST is retried as GET when Save Frame As used, and the
+ * page is no longer in the cache.
+ */
+function test() {
+  waitForExplicitFinish();
+
+  BrowserTestUtils.loadURI(
+    gBrowser,
+    "http://mochi.test:8888/browser/toolkit/content/tests/browser/data/post_form_outer.sjs"
+  );
+
+  gBrowser.addEventListener("pageshow", function pageShown(event) {
+    if (event.target.location == "about:blank") {
+      return;
+    }
+    gBrowser.removeEventListener("pageshow", pageShown);
+
+    // Submit the form in the outer page, then wait for both the outer
+    // document and the inner frame to be loaded again.
+    gBrowser.addEventListener("DOMContentLoaded", handleOuterSubmit);
+    gBrowser.contentDocument.getElementById("postForm").submit();
+  });
+
+  var framesLoaded = 0;
+  var innerFrame;
+
+  function handleOuterSubmit() {
+    if (++framesLoaded < 2) {
+      return;
+    }
+
+    gBrowser.removeEventListener("DOMContentLoaded", handleOuterSubmit);
+
+    innerFrame = gBrowser.contentDocument.getElementById("innerFrame");
+
+    // Submit the form in the inner page.
+    gBrowser.addEventListener("DOMContentLoaded", handleInnerSubmit);
+    innerFrame.contentDocument.getElementById("postForm").submit();
+  }
+
+  function handleInnerSubmit() {
+    gBrowser.removeEventListener("DOMContentLoaded", handleInnerSubmit);
+
+    // Create the folder the page will be saved into.
+    var destDir = createTemporarySaveDirectory();
+    var file = destDir.clone();
+    file.append("no_default_file_name");
+    MockFilePicker.setFiles([file]);
+    MockFilePicker.showCallback = function(fp) {
+      MockFilePicker.filterIndex = 1; // kSaveAsType_URL
+    };
+
+    mockTransferCallback = onTransferComplete;
+    mockTransferRegisterer.register();
+
+    registerCleanupFunction(function() {
+      mockTransferRegisterer.unregister();
+      MockFilePicker.cleanup();
+      destDir.remove(true);
+    });
+
+    var docToSave = innerFrame.contentDocument;
+    // We call internalSave instead of saveDocument to bypass the history
+    // cache.
+    internalSave(
+      docToSave.location.href,
+      docToSave,
+      null,
+      null,
+      docToSave.contentType,
+      false,
+      null,
+      null,
+      docToSave.referrer ? makeURI(docToSave.referrer) : null,
+      docToSave,
+      false,
+      null
+    );
+  }
+
+  function onTransferComplete(downloadSuccess) {
+    ok(
+      downloadSuccess,
+      "The inner frame should have been downloaded successfully"
+    );
+
+    // Read the entire saved file.
+    var file = MockFilePicker.getNsIFile();
+    var fileContents = readShortFile(file);
+
+    // Check if outer POST data is found (bug 471962).
+    is(
+      fileContents.indexOf("inputfield=outer"),
+      -1,
+      "The saved inner frame does not contain outer POST data"
+    );
+
+    // Check if inner POST data is found (bug 485196).
+    isnot(
+      fileContents.indexOf("inputfield=inner"),
+      -1,
+      "The saved inner frame was generated using the correct POST data"
+    );
+
+    finish();
+  }
+}
+
+/* import-globals-from common/mockTransfer.js */
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/toolkit/content/tests/browser/common/mockTransfer.js",
+  this
+);
+
+function createTemporarySaveDirectory() {
+  var saveDir = Services.dirsvc.get("TmpD", Ci.nsIFile);
+  saveDir.append("testsavedir");
+  if (!saveDir.exists()) {
+    saveDir.create(Ci.nsIFile.DIRECTORY_TYPE, 0o755);
+  }
+  return saveDir;
+}
+
+/**
+ * Reads the contents of the provided short file (up to 1 MiB).
+ *
+ * @param aFile
+ *        nsIFile object pointing to the file to be read.
+ *
+ * @return
+ *        String containing the raw octets read from the file.
+ */
+function readShortFile(aFile) {
+  var inputStream = Cc[
+    "@mozilla.org/network/file-input-stream;1"
+  ].createInstance(Ci.nsIFileInputStream);
+  inputStream.init(aFile, -1, 0, 0);
+  try {
+    var scrInputStream = Cc[
+      "@mozilla.org/scriptableinputstream;1"
+    ].createInstance(Ci.nsIScriptableInputStream);
+    scrInputStream.init(inputStream);
+    try {
+      // Assume that the file is much shorter than 1 MiB.
+      return scrInputStream.read(1048576);
+    } finally {
+      // Close the scriptable stream after reading, even if the operation
+      // failed.
+      scrInputStream.close();
+    }
+  } finally {
+    // Close the stream after reading, if it is still open, even if the read
+    // operation failed.
+    inputStream.close();
+  }
+}
diff --git a/toolkit/content/tests/browser/browser_suspend_videos_outside_viewport.js b/toolkit/content/tests/browser/browser_suspend_videos_outside_viewport.js
new file mode 100644
index 0000000000..333bd0d41c
--- /dev/null
+++ b/toolkit/content/tests/browser/browser_suspend_videos_outside_viewport.js
@@ -0,0 +1,39 @@
+/**
+ * This test is used to ensure we suspend video decoding if video is not in the
+ * viewport.
+ */
+"use strict";
+
+const PAGE =
+  "https://example.com/browser/toolkit/content/tests/browser/file_outside_viewport_videos.html";
+
+async function test_suspend_video_decoding() {
+  let videos = content.document.getElementsByTagName("video");
+  for (let video of videos) {
+    info(`- start video on the ${video.id} side and outside the viewport -`);
+    await video.play();
+    ok(true, `video started playing`);
+    ok(video.isVideoDecodingSuspended, `video decoding is suspended`);
+  }
+}
+
+add_task(async function setup_test_preference() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["media.suspend-bkgnd-video.enabled", true],
+      ["media.suspend-bkgnd-video.delay-ms", 0],
+    ],
+  });
+});
+
+add_task(async function start_test() {
+  await BrowserTestUtils.withNewTab(
+    {
+      gBrowser,
+      url: PAGE,
+    },
+    async browser => {
+      await SpecialPowers.spawn(browser, [], test_suspend_video_decoding);
+    }
+  );
+});
diff --git a/toolkit/content/tests/browser/common/mockTransfer.js b/toolkit/content/tests/browser/common/mockTransfer.js
new file mode 100644
index 0000000000..f4afa44903
--- /dev/null
+++ b/toolkit/content/tests/browser/common/mockTransfer.js
@@ -0,0 +1,85 @@
+/* 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/. */
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochikit/content/tests/SimpleTest/MockObjects.js",
+  this
+);
+
+var mockTransferCallback;
+
+/**
+ * This "transfer" object implementation continues the currently running test
+ * when the download is completed, reporting true for success or false for
+ * failure as the first argument of the testRunner.continueTest function.
+ */
+function MockTransfer() {
+  this._downloadIsSuccessful = true;
+}
+
+MockTransfer.prototype = {
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIWebProgressListener",
+    "nsIWebProgressListener2",
+    "nsITransfer",
+  ]),
+
+  /* nsIWebProgressListener */
+  onStateChange: function MTFC_onStateChange(
+    aWebProgress,
+    aRequest,
+    aStateFlags,
+    aStatus
+  ) {
+    // If at least one notification reported an error, the download failed.
+    if (!Components.isSuccessCode(aStatus)) {
+      this._downloadIsSuccessful = false;
+    }
+
+    // If the download is finished
+    if (
+      aStateFlags & Ci.nsIWebProgressListener.STATE_STOP &&
+      aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK
+    ) {
+      // Continue the test, reporting the success or failure condition.
+      mockTransferCallback(this._downloadIsSuccessful);
+    }
+  },
+  onProgressChange() {},
+  onLocationChange() {},
+  onStatusChange: function MTFC_onStatusChange(
+    aWebProgress,
+    aRequest,
+    aStatus,
+    aMessage
+  ) {
+    // If at least one notification reported an error, the download failed.
+    if (!Components.isSuccessCode(aStatus)) {
+      this._downloadIsSuccessful = false;
+    }
+  },
+  onSecurityChange() {},
+  onContentBlockingEvent() {},
+
+  /* nsIWebProgressListener2 */
+  onProgressChange64() {},
+  onRefreshAttempted() {},
+
+  /* nsITransfer */
+  init() {},
+  initWithBrowsingContext() {},
+  setSha256Hash() {},
+  setSignatureInfo() {},
+};
+
+// Create an instance of a MockObjectRegisterer whose methods can be used to
+// temporarily replace the default "@mozilla.org/transfer;1" object factory with
+// one that provides the mock implementation above. To activate the mock object
+// factory, call the "register" method. Starting from that moment, all the
+// transfer objects that are requested will be mock objects, until the
+// "unregister" method is called.
+var mockTransferRegisterer = new MockObjectRegisterer(
+  "@mozilla.org/transfer;1",
+  MockTransfer
+);
diff --git a/toolkit/content/tests/browser/data/post_form_inner.sjs b/toolkit/content/tests/browser/data/post_form_inner.sjs
new file mode 100644
index 0000000000..ce72159d81
--- /dev/null
+++ b/toolkit/content/tests/browser/data/post_form_inner.sjs
@@ -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/. */
+
+const CC = Components.Constructor;
+const BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",
+                             "nsIBinaryInputStream",
+                             "setInputStream");
+
+function handleRequest(request, response)
+{
+  var body =
+   '<html>\
+    <body>\
+    Inner POST data: ';
+
+  var bodyStream = new BinaryInputStream(request.bodyInputStream);
+  var bytes = [], avail = 0;
+  while ((avail = bodyStream.available()) > 0)
+   body += String.fromCharCode.apply(String, bodyStream.readByteArray(avail));
+
+  body +=
+    '<form id="postForm" action="post_form_inner.sjs" method="post">\
+     <input type="text" name="inputfield" value="inner">\
+     <input type="submit">\
+     </form>\
+     </body>\
+     </html>';
+
+  response.bodyOutputStream.write(body, body.length);
+}
diff --git a/toolkit/content/tests/browser/data/post_form_outer.sjs b/toolkit/content/tests/browser/data/post_form_outer.sjs
new file mode 100644
index 0000000000..89256fcfb2
--- /dev/null
+++ b/toolkit/content/tests/browser/data/post_form_outer.sjs
@@ -0,0 +1,34 @@
+/* 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 CC = Components.Constructor;
+const BinaryInputStream = CC("@mozilla.org/binaryinputstream;1",
+                             "nsIBinaryInputStream",
+                             "setInputStream");
+
+function handleRequest(request, response)
+{
+  var body =
+   '<html>\
+    <body>\
+    Outer POST data: ';
+
+  var bodyStream = new BinaryInputStream(request.bodyInputStream);
+  var bytes = [], avail = 0;
+  while ((avail = bodyStream.available()) > 0)
+   body += String.fromCharCode.apply(String, bodyStream.readByteArray(avail));
+
+  body +=
+    '<form id="postForm" action="post_form_outer.sjs" method="post">\
+     <input type="text" name="inputfield" value="outer">\
+     <input type="submit">\
+     </form>\
+     \
+     <iframe id="innerFrame" src="post_form_inner.sjs" width="400" height="200">\
+     \
+     </body>\
+     </html>';
+
+  response.bodyOutputStream.write(body, body.length);
+}
diff --git a/toolkit/content/tests/browser/doggy.png b/toolkit/content/tests/browser/doggy.png
new file mode 100644
index 0000000000..73632d3229
--- /dev/null
+++ b/toolkit/content/tests/browser/doggy.png
diff --git a/toolkit/content/tests/browser/empty.png b/toolkit/content/tests/browser/empty.png
new file mode 100644
index 0000000000..17ddf0c3ee
--- /dev/null
+++ b/toolkit/content/tests/browser/empty.png
diff --git a/toolkit/content/tests/browser/file_contentTitle.html b/toolkit/content/tests/browser/file_contentTitle.html
new file mode 100644
index 0000000000..8d330aa0f2
--- /dev/null
+++ b/toolkit/content/tests/browser/file_contentTitle.html
@@ -0,0 +1,14 @@
+<html>
+<head><title>Test Page</title></head>
+<body>
+<script type="text/javascript">
+dump("Script!\n");
+addEventListener("load", () => {
+  // Trigger an onLocationChange event. We want to make sure the title is still correct afterwards.
+  location.hash = "#x2";
+  var event = new Event("TestLocationChange");
+  document.dispatchEvent(event);
+}, false);
+</script>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_document_open_audio.html b/toolkit/content/tests/browser/file_document_open_audio.html
new file mode 100644
index 0000000000..1234299c67
--- /dev/null
+++ b/toolkit/content/tests/browser/file_document_open_audio.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<title>Test for bug 1572798</title>
+<script>
+  function openVideo() {
+    var w = window.open('', '', 'width = 640, height = 480, scrollbars=yes, menubar=no, toolbar=no, resizable=yes');
+    w.document.open();
+    w.document.write('<!DOCTYPE html><title>test popup</title><audio controls src="audio.ogg"></audio>');
+    w.document.close();
+  }
+</script>
+<button onclick="openVideo()">Open video</button>
diff --git a/toolkit/content/tests/browser/file_empty.html b/toolkit/content/tests/browser/file_empty.html
new file mode 100644
index 0000000000..d2b0361f09
--- /dev/null
+++ b/toolkit/content/tests/browser/file_empty.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Page left intentionally blank...</title>
+  </head>
+  <body>
+  </body>
+</html>
diff --git a/toolkit/content/tests/browser/file_findinframe.html b/toolkit/content/tests/browser/file_findinframe.html
new file mode 100644
index 0000000000..27a9d00a97
--- /dev/null
+++ b/toolkit/content/tests/browser/file_findinframe.html
@@ -0,0 +1,5 @@
+<html>
+  <body>
+    <iframe src="data:text/html,&lt;body contenteditable&gt;Test&lt;/body&gt;"></iframe>
+  </body>
+</html>
diff --git a/toolkit/content/tests/browser/file_mediaPlayback2.html b/toolkit/content/tests/browser/file_mediaPlayback2.html
new file mode 100644
index 0000000000..890b494a05
--- /dev/null
+++ b/toolkit/content/tests/browser/file_mediaPlayback2.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<body>
+<script type="text/javascript">
+var audio = new Audio();
+audio.oncanplay = function() {
+  audio.oncanplay = null;
+  audio.play();
+};
+audio.src = "audio.ogg";
+audio.loop = true;
+audio.id = "v";
+document.body.appendChild(audio);
+</script>
+</body>
diff --git a/toolkit/content/tests/browser/file_multipleAudio.html b/toolkit/content/tests/browser/file_multipleAudio.html
new file mode 100644
index 0000000000..5dc37febb4
--- /dev/null
+++ b/toolkit/content/tests/browser/file_multipleAudio.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <meta content="utf-8" http-equiv="encoding">
+</head>
+<body>
+<audio id="autoplay" src="audio.ogg"></audio>
+<audio id="nonautoplay" src="audio.ogg"></audio>
+<script type="text/javascript">
+
+// In linux debug on try server, sometimes the download process would fail, so
+// we can't activate the "auto-play" or playing after receving "oncanplay".
+// Therefore, we just call play here.
+var audio = document.getElementById("autoplay");
+audio.loop = true;
+audio.play();
+
+</script>
+</body>
diff --git a/toolkit/content/tests/browser/file_multiplePlayingAudio.html b/toolkit/content/tests/browser/file_multiplePlayingAudio.html
new file mode 100644
index 0000000000..ae122506fb
--- /dev/null
+++ b/toolkit/content/tests/browser/file_multiplePlayingAudio.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <meta content="utf-8" http-equiv="encoding">
+</head>
+<body>
+<audio id="audio1" src="audio.ogg" controls></audio>
+<audio id="audio2" src="audio.ogg" controls></audio>
+<script type="text/javascript">
+
+// In linux debug on try server, sometimes the download process would fail, so
+// we can't activate the "auto-play" or playing after receving "oncanplay".
+// Therefore, we just call play here.
+var audio1 = document.getElementById("audio1");
+audio1.loop = true;
+audio1.play();
+
+var audio2 = document.getElementById("audio2");
+audio2.loop = true;
+audio2.play();
+
+</script>
+</body>
diff --git a/toolkit/content/tests/browser/file_nonAutoplayAudio.html b/toolkit/content/tests/browser/file_nonAutoplayAudio.html
new file mode 100644
index 0000000000..4d2641021a
--- /dev/null
+++ b/toolkit/content/tests/browser/file_nonAutoplayAudio.html
@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <meta content="utf-8" http-equiv="encoding">
+</head>
+<body>
+<audio id="testAudio" src="audio.ogg" loop></audio>
diff --git a/toolkit/content/tests/browser/file_outside_viewport_videos.html b/toolkit/content/tests/browser/file_outside_viewport_videos.html
new file mode 100644
index 0000000000..84aa34358d
--- /dev/null
+++ b/toolkit/content/tests/browser/file_outside_viewport_videos.html
@@ -0,0 +1,41 @@
+<html>
+<head>
+  <title>outside viewport videos</title>
+<style>
+/**
+ * These CSS would move elements to the far left/right/top/bottom where user
+ * can not see elements in the viewport if user doesn't scroll the page.
+ */
+.outside-left {
+  position: absolute;
+  left: -1000%;
+}
+.outside-right {
+  position: absolute;
+  right: -1000%;
+}
+.outside-top {
+  position: absolute;
+  top: -1000%;
+}
+.outside-bottom {
+  position: absolute;
+  bottom: -1000%;
+}
+</style>
+</head>
+<body>
+	<div class="outside-left">
+		<video id="left" src="gizmo.mp4">
+	</div>
+	<div class="outside-right">
+		<video id="right" src="gizmo.mp4">
+	</div>
+	<div class="outside-top">
+		<video id="top" src="gizmo.mp4">
+	</div>
+	<div class="outside-bottom">
+		<video id="bottom" src="gizmo.mp4">
+	</div>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_redirect.html b/toolkit/content/tests/browser/file_redirect.html
new file mode 100644
index 0000000000..4d5fa9dfd1
--- /dev/null
+++ b/toolkit/content/tests/browser/file_redirect.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>redirecting...</title>
+<script>
+window.addEventListener("load",
+  () => window.location = "file_redirect_to.html");
+</script>
+<body>
+redirectin u bro
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_redirect_to.html b/toolkit/content/tests/browser/file_redirect_to.html
new file mode 100644
index 0000000000..28c0b53713
--- /dev/null
+++ b/toolkit/content/tests/browser/file_redirect_to.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>redirected!</title>
+<script>
+window.addEventListener("load", () => {
+  var event = new Event("RedirectDone");
+  document.dispatchEvent(event);
+});
+</script>
+<body>
+u got redirected, bro
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_silentAudioTrack.html b/toolkit/content/tests/browser/file_silentAudioTrack.html
new file mode 100644
index 0000000000..afdf2c5297
--- /dev/null
+++ b/toolkit/content/tests/browser/file_silentAudioTrack.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <meta content="utf-8" http-equiv="encoding">
+</head>
+<body>
+<video id="autoplay" src="silentAudioTrack.webm"></video>
+<script type="text/javascript">
+
+// In linux debug on try server, sometimes the download process would fail, so
+// we can't activate the "auto-play" or playing after receving "oncanplay".
+// Therefore, we just call play here.
+var video = document.getElementById("autoplay");
+video.loop = true;
+video.play();
+
+</script>
+</body>
diff --git a/toolkit/content/tests/browser/file_video.html b/toolkit/content/tests/browser/file_video.html
new file mode 100644
index 0000000000..3c70268fbb
--- /dev/null
+++ b/toolkit/content/tests/browser/file_video.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>video</title>
+</head>
+<body>
+<video id="v" src="gizmo.mp4" controls loop></video>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_videoWithAudioOnly.html b/toolkit/content/tests/browser/file_videoWithAudioOnly.html
new file mode 100644
index 0000000000..be84d60c34
--- /dev/null
+++ b/toolkit/content/tests/browser/file_videoWithAudioOnly.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>video</title>
+</head>
+<body>
+<video id="v" src="audio.ogg" controls loop></video>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_videoWithoutAudioTrack.html b/toolkit/content/tests/browser/file_videoWithoutAudioTrack.html
new file mode 100644
index 0000000000..a732b7c9d0
--- /dev/null
+++ b/toolkit/content/tests/browser/file_videoWithoutAudioTrack.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<title>video without audio track</title>
+</head>
+<body>
+<video id="v" src="gizmo-noaudio.webm" controls loop></video>
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/file_webAudio.html b/toolkit/content/tests/browser/file_webAudio.html
new file mode 100644
index 0000000000..f6fb5e7c07
--- /dev/null
+++ b/toolkit/content/tests/browser/file_webAudio.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<head>
+  <meta content="text/html;charset=utf-8" http-equiv="Content-Type">
+  <meta content="utf-8" http-equiv="encoding">
+</head>
+<body>
+<pre id=state></pre>
+<button id="start" onclick="start_webaudio()">Start</button>
+<button id="stop" onclick="stop_webaudio()">Stop</button>
+<script type="text/javascript">
+  var ac = new AudioContext();
+  var dest = ac.destination;
+  var osc = ac.createOscillator();
+  osc.connect(dest);
+  osc.start();
+  document.querySelector("pre").innerText = ac.state;
+  ac.onstatechange = function() {
+    document.querySelector("pre").innerText = ac.state;
+  }
+
+  function start_webaudio() {
+    ac.resume();
+  }
+
+  function stop_webaudio() {
+    ac.suspend();
+  }
+</script>
+</body>
diff --git a/toolkit/content/tests/browser/firebird.png b/toolkit/content/tests/browser/firebird.png
new file mode 100644
index 0000000000..de5c22f8ce
--- /dev/null
+++ b/toolkit/content/tests/browser/firebird.png
diff --git a/toolkit/content/tests/browser/firebird.png^headers^ b/toolkit/content/tests/browser/firebird.png^headers^
new file mode 100644
index 0000000000..2918fdbe5f
--- /dev/null
+++ b/toolkit/content/tests/browser/firebird.png^headers^
@@ -0,0 +1,2 @@
+HTTP 302 Found
+Location: doggy.png
diff --git a/toolkit/content/tests/browser/gizmo-noaudio.webm b/toolkit/content/tests/browser/gizmo-noaudio.webm
new file mode 100644
index 0000000000..9f412cb6e3
--- /dev/null
+++ b/toolkit/content/tests/browser/gizmo-noaudio.webm
diff --git a/toolkit/content/tests/browser/gizmo.mp4 b/toolkit/content/tests/browser/gizmo.mp4
new file mode 100644
index 0000000000..87efad5ade
--- /dev/null
+++ b/toolkit/content/tests/browser/gizmo.mp4
diff --git a/toolkit/content/tests/browser/head.js b/toolkit/content/tests/browser/head.js
new file mode 100644
index 0000000000..8973f1a6b4
--- /dev/null
+++ b/toolkit/content/tests/browser/head.js
@@ -0,0 +1,338 @@
+"use strict";
+
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm", this);
+
+/**
+ * A wrapper for the findbar's method "close", which is not synchronous
+ * because of animation.
+ */
+function closeFindbarAndWait(findbar) {
+  return new Promise(resolve => {
+    if (findbar.hidden) {
+      resolve();
+      return;
+    }
+    findbar.addEventListener("transitionend", function cont(aEvent) {
+      if (aEvent.propertyName != "visibility") {
+        return;
+      }
+      findbar.removeEventListener("transitionend", cont);
+      resolve();
+    });
+    let close = findbar.getElement("find-closebutton");
+    close.doCommand();
+  });
+}
+
+function pushPrefs(...aPrefs) {
+  return new Promise(resolve => {
+    SpecialPowers.pushPrefEnv({ set: aPrefs }, resolve);
+  });
+}
+
+/**
+ * Used to check whether the audio unblocking icon is in the tab.
+ */
+async function waitForTabBlockEvent(tab, expectBlocked) {
+  if (tab.activeMediaBlocked == expectBlocked) {
+    ok(true, "The tab should " + (expectBlocked ? "" : "not ") + "be blocked");
+  } else {
+    info("Block state doens't match, wait for attributes changes.");
+    await BrowserTestUtils.waitForEvent(
+      tab,
+      "TabAttrModified",
+      false,
+      event => {
+        if (event.detail.changed.includes("activemedia-blocked")) {
+          is(
+            tab.activeMediaBlocked,
+            expectBlocked,
+            "The tab should " + (expectBlocked ? "" : "not ") + "be blocked"
+          );
+          return true;
+        }
+        return false;
+      }
+    );
+  }
+}
+
+/**
+ * Used to check whether the tab has soundplaying attribute.
+ */
+async function waitForTabPlayingEvent(tab, expectPlaying) {
+  if (tab.soundPlaying == expectPlaying) {
+    ok(true, "The tab should " + (expectPlaying ? "" : "not ") + "be playing");
+  } else {
+    info("Playing state doesn't match, wait for attributes changes.");
+    await BrowserTestUtils.waitForEvent(
+      tab,
+      "TabAttrModified",
+      false,
+      event => {
+        if (event.detail.changed.includes("soundplaying")) {
+          is(
+            tab.soundPlaying,
+            expectPlaying,
+            "The tab should " + (expectPlaying ? "" : "not ") + "be playing"
+          );
+          return true;
+        }
+        return false;
+      }
+    );
+  }
+}
+
+function getTestPlugin(pluginName) {
+  var ph = SpecialPowers.Cc["@mozilla.org/plugin/host;1"].getService(
+    SpecialPowers.Ci.nsIPluginHost
+  );
+  var tags = ph.getPluginTags();
+  var name = pluginName || "Test Plug-in";
+  for (var tag of tags) {
+    if (tag.name == name) {
+      return tag;
+    }
+  }
+
+  ok(false, "Could not find plugin tag with plugin name '" + name + "'");
+  return null;
+}
+
+async function setTestPluginEnabledState(newEnabledState, pluginName) {
+  var oldEnabledState = await SpecialPowers.setTestPluginEnabledState(
+    newEnabledState,
+    pluginName
+  );
+  if (!oldEnabledState) {
+    return;
+  }
+  var plugin = getTestPlugin(pluginName);
+  // Run a nested event loop to wait for the preference change to
+  // propagate to the child. Yuck!
+  SpecialPowers.Services.tm.spinEventLoopUntil(() => {
+    return plugin.enabledState == newEnabledState;
+  });
+  SimpleTest.registerCleanupFunction(function() {
+    return SpecialPowers.setTestPluginEnabledState(oldEnabledState, pluginName);
+  });
+}
+
+function disable_non_test_mouse(disable) {
+  let utils = window.windowUtils;
+  utils.disableNonTestMouseEvents(disable);
+}
+
+function hover_icon(icon, tooltip) {
+  disable_non_test_mouse(true);
+
+  let popupShownPromise = BrowserTestUtils.waitForEvent(tooltip, "popupshown");
+  EventUtils.synthesizeMouse(icon, 1, 1, { type: "mouseover" });
+  EventUtils.synthesizeMouse(icon, 2, 2, { type: "mousemove" });
+  EventUtils.synthesizeMouse(icon, 3, 3, { type: "mousemove" });
+  EventUtils.synthesizeMouse(icon, 4, 4, { type: "mousemove" });
+  return popupShownPromise;
+}
+
+function leave_icon(icon) {
+  EventUtils.synthesizeMouse(icon, 0, 0, { type: "mouseout" });
+  EventUtils.synthesizeMouseAtCenter(document.documentElement, {
+    type: "mousemove",
+  });
+  EventUtils.synthesizeMouseAtCenter(document.documentElement, {
+    type: "mousemove",
+  });
+  EventUtils.synthesizeMouseAtCenter(document.documentElement, {
+    type: "mousemove",
+  });
+
+  disable_non_test_mouse(false);
+}
+
+/**
+ * Helper class for testing datetime input picker widget
+ */
+class DateTimeTestHelper {
+  constructor() {
+    this.panel = gBrowser._getAndMaybeCreateDateTimePickerPanel();
+    this.panel.setAttribute("animate", false);
+    this.tab = null;
+    this.frame = null;
+  }
+
+  /**
+   * Opens a new tab with the URL of the test page, and make sure the picker is
+   * ready for testing.
+   *
+   * @param  {String} pageUrl
+   * @param  {bool} inFrame true if input is in the first child frame
+   */
+  async openPicker(pageUrl, inFrame) {
+    this.tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, pageUrl);
+    let bc = gBrowser.selectedBrowser;
+    if (inFrame) {
+      await SpecialPowers.spawn(bc, [], async function() {
+        const iframe = content.document.querySelector("iframe");
+        // Ensure the iframe's position is correct before doing any
+        // other operations
+        iframe.getBoundingClientRect();
+      });
+      bc = bc.browsingContext.children[0];
+    }
+    await BrowserTestUtils.synthesizeMouseAtCenter("input", {}, bc);
+    this.frame = this.panel.querySelector("#dateTimePopupFrame");
+    await this.waitForPickerReady();
+  }
+
+  promisePickerClosed() {
+    return new Promise(resolve => {
+      this.panel.addEventListener("popuphidden", resolve, { once: true });
+    });
+  }
+
+  async waitForPickerReady() {
+    let readyPromise;
+    let loadPromise = new Promise(resolve => {
+      this.frame.addEventListener(
+        "load",
+        () => {
+          // Add the PickerReady event listener directly inside the load event
+          // listener to avoid missing the event.
+          readyPromise = BrowserTestUtils.waitForEvent(
+            this.frame.contentDocument,
+            "PickerReady"
+          );
+          resolve();
+        },
+        { capture: true, once: true }
+      );
+    });
+
+    await loadPromise;
+    // Wait for picker elements to be ready
+    await readyPromise;
+  }
+
+  /**
+   * Find an element on the picker.
+   *
+   * @param  {String} selector
+   * @return {DOMElement}
+   */
+  getElement(selector) {
+    return this.frame.contentDocument.querySelector(selector);
+  }
+
+  /**
+   * Find the children of an element on the picker.
+   *
+   * @param  {String} selector
+   * @return {Array<DOMElement>}
+   */
+  getChildren(selector) {
+    return Array.from(this.getElement(selector).children);
+  }
+
+  /**
+   * Click on an element
+   *
+   * @param  {DOMElement} element
+   */
+  click(element) {
+    EventUtils.synthesizeMouseAtCenter(element, {}, this.frame.contentWindow);
+  }
+
+  /**
+   * Close the panel and the tab
+   */
+  async tearDown() {
+    if (!this.panel.hidden) {
+      let pickerClosePromise = this.promisePickerClosed();
+      this.panel.hidePopup();
+      await pickerClosePromise;
+    }
+    BrowserTestUtils.removeTab(this.tab);
+    this.tab = null;
+  }
+
+  /**
+   * Clean up after tests. Remove the frame to prevent leak.
+   */
+  cleanup() {
+    this.frame.remove();
+    this.frame = null;
+    this.panel.removeAttribute("animate");
+    this.panel = null;
+  }
+}
+
+/**
+ * Used to listen events if you just need it once
+ */
+function once(target, name) {
+  var p = new Promise(function(resolve, reject) {
+    target.addEventListener(
+      name,
+      function() {
+        resolve();
+      },
+      { once: true }
+    );
+  });
+  return p;
+}
+
+/**
+ * check if current wakelock is equal to expected state, if not, then wait until
+ * the wakelock changes its state to expected state.
+ * @param needLock
+ *        the wakolock should be locked or not
+ * @param isForegroundLock
+ *        when the lock is on, the wakelock should be in the foreground or not
+ */
+async function waitForExpectedWakeLockState(
+  topic,
+  { needLock, isForegroundLock }
+) {
+  const powerManagerService = Cc["@mozilla.org/power/powermanagerservice;1"];
+  const powerManager = powerManagerService.getService(
+    Ci.nsIPowerManagerService
+  );
+  const wakelockState = powerManager.getWakeLockState(topic);
+  let expectedLockState = "unlocked";
+  if (needLock) {
+    expectedLockState = isForegroundLock
+      ? "locked-foreground"
+      : "locked-background";
+  }
+  if (wakelockState != expectedLockState) {
+    info(`wait until wakelock becomes ${expectedLockState}`);
+    await wakeLockObserved(
+      powerManager,
+      topic,
+      state => state == expectedLockState
+    );
+  }
+  is(
+    powerManager.getWakeLockState(topic),
+    expectedLockState,
+    `the wakelock state for '${topic}' is equal to '${expectedLockState}'`
+  );
+}
+
+function wakeLockObserved(powerManager, observeTopic, checkFn) {
+  return new Promise(resolve => {
+    function wakeLockListener() {}
+    wakeLockListener.prototype = {
+      QueryInterface: ChromeUtils.generateQI(["nsIDOMMozWakeLockListener"]),
+      callback(topic, state) {
+        if (topic == observeTopic && checkFn(state)) {
+          powerManager.removeWakeLockListener(wakeLockListener.prototype);
+          resolve();
+        }
+      },
+    };
+    powerManager.addWakeLockListener(wakeLockListener.prototype);
+  });
+}
diff --git a/toolkit/content/tests/browser/image.jpg b/toolkit/content/tests/browser/image.jpg
new file mode 100644
index 0000000000..5031808ad2
--- /dev/null
+++ b/toolkit/content/tests/browser/image.jpg
diff --git a/toolkit/content/tests/browser/image_page.html b/toolkit/content/tests/browser/image_page.html
new file mode 100644
index 0000000000..522a1d8cf9
--- /dev/null
+++ b/toolkit/content/tests/browser/image_page.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>OHAI</title>
+<body>
+<img id="image" src="image.jpg" />
+</body>
+</html>
diff --git a/toolkit/content/tests/browser/silentAudioTrack.webm b/toolkit/content/tests/browser/silentAudioTrack.webm
new file mode 100644
index 0000000000..8e08a86c45
--- /dev/null
+++ b/toolkit/content/tests/browser/silentAudioTrack.webm