Adding upstream version 86.0.1.upstream/86.0.1upstream

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

1 files changed, 2284 insertions, 0 deletions

diff --git a/tools/profiler/tests/gtest/GeckoProfiler.cpp b/tools/profiler/tests/gtest/GeckoProfiler.cpp
new file mode 100644
index 0000000000..bacf34e3d5
--- /dev/null
+++ b/tools/profiler/tests/gtest/GeckoProfiler.cpp
@@ -0,0 +1,2284 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This file tests a lot of the profiler_*() functions in GeckoProfiler.h.
+// Most of the tests just check that nothing untoward (e.g. crashes, deadlocks)
+// happens when calling these functions. They don't do much inspection of
+// profiler internals.
+
+#include "GeckoProfiler.h"
+#include "mozilla/ProfilerMarkerTypes.h"
+#include "mozilla/ProfilerMarkers.h"
+#include "platform.h"
+#include "ProfileBuffer.h"
+
+#include "js/Initialization.h"
+#include "js/Printf.h"
+#include "jsapi.h"
+#include "json/json.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/BlocksRingBuffer.h"
+#include "mozilla/ProfileBufferEntrySerializationGeckoExtensions.h"
+#include "mozilla/ProfileJSONWriter.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/net/HttpBaseChannel.h"
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+
+#include "gtest/gtest.h"
+
+#include <cstring>
+#include <set>
+#include <thread>
+
+// Note: profiler_init() has already been called in XRE_main(), so we can't
+// test it here. Likewise for profiler_shutdown(), and AutoProfilerInit
+// (which is just an RAII wrapper for profiler_init() and profiler_shutdown()).
+
+using namespace mozilla;
+
+TEST(BaseProfiler, BlocksRingBuffer)
+{
+  constexpr uint32_t MBSize = 256;
+  uint8_t buffer[MBSize * 3];
+  for (size_t i = 0; i < MBSize * 3; ++i) {
+    buffer[i] = uint8_t('A' + i);
+  }
+  BlocksRingBuffer rb(BlocksRingBuffer::ThreadSafety::WithMutex,
+                      &buffer[MBSize], MakePowerOfTwo32<MBSize>());
+
+  {
+    nsCString cs("nsCString"_ns);
+    nsString s(u"nsString"_ns);
+    nsAutoCString acs("nsAutoCString"_ns);
+    nsAutoString as(u"nsAutoString"_ns);
+    nsAutoCStringN<8> acs8("nsAutoCStringN"_ns);
+    nsAutoStringN<8> as8(u"nsAutoStringN"_ns);
+    JS::UniqueChars jsuc = JS_smprintf("%s", "JS::UniqueChars");
+
+    rb.PutObjects(cs, s, acs, as, acs8, as8, jsuc);
+  }
+
+  rb.ReadEach([](ProfileBufferEntryReader& aER) {
+    ASSERT_EQ(aER.ReadObject<nsCString>(), "nsCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsString>(), u"nsString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCString>(), "nsAutoCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoString>(), u"nsAutoString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCStringN<8>>(), "nsAutoCStringN"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoStringN<8>>(), u"nsAutoStringN"_ns);
+    auto jsuc2 = aER.ReadObject<JS::UniqueChars>();
+    ASSERT_TRUE(!!jsuc2);
+    ASSERT_TRUE(strcmp(jsuc2.get(), "JS::UniqueChars") == 0);
+  });
+
+  // Everything around the sub-buffer should be unchanged.
+  for (size_t i = 0; i < MBSize; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+  for (size_t i = MBSize * 2; i < MBSize * 3; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+}
+
+// Common JSON checks.
+
+// Does the GETTER return a non-null TYPE? (Non-critical)
+#define EXPECT_HAS_JSON(GETTER, TYPE)                                         \
+  do {                                                                        \
+    if ((GETTER).isNull()) {                                                  \
+      EXPECT_FALSE((GETTER).isNull()) << #GETTER " doesn't exist or is null"; \
+    } else if (!(GETTER).is##TYPE()) {                                        \
+      EXPECT_TRUE((GETTER).is##TYPE())                                        \
+          << #GETTER " didn't return type " #TYPE;                            \
+    }                                                                         \
+  } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+#define ASSERT_HAS_JSON(GETTER, TYPE) \
+  do {                                \
+    ASSERT_FALSE((GETTER).isNull());  \
+    ASSERT_TRUE((GETTER).is##TYPE()); \
+  } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+// If yes, store the value into VARIABLE.
+#define GET_JSON(VARIABLE, GETTER, TYPE) \
+  ASSERT_HAS_JSON(GETTER, TYPE);         \
+  const Json::Value& VARIABLE = (GETTER)
+
+// Checks that the GETTER's value is present, is of the expected TYPE, and has
+// the expected VALUE. (Non-critical)
+#define EXPECT_EQ_JSON(GETTER, TYPE, VALUE)                                   \
+  do {                                                                        \
+    if ((GETTER).isNull()) {                                                  \
+      EXPECT_FALSE((GETTER).isNull()) << #GETTER " doesn't exist or is null"; \
+    } else if (!(GETTER).is##TYPE()) {                                        \
+      EXPECT_TRUE((GETTER).is##TYPE())                                        \
+          << #GETTER " didn't return type " #TYPE;                            \
+    } else {                                                                  \
+      EXPECT_EQ((GETTER).as##TYPE(), (VALUE));                                \
+    }                                                                         \
+  } while (false)
+
+// Checks that the GETTER's value is present, and is a valid index into the
+// STRINGTABLE array, pointing at the expected STRING.
+#define EXPECT_EQ_STRINGTABLE(GETTER, STRINGTABLE, STRING)                    \
+  do {                                                                        \
+    if ((GETTER).isNull()) {                                                  \
+      EXPECT_FALSE((GETTER).isNull()) << #GETTER " doesn't exist or is null"; \
+    } else if (!(GETTER).isUInt()) {                                          \
+      EXPECT_TRUE((GETTER).isUInt()) << #GETTER " didn't return an index";    \
+    } else {                                                                  \
+      EXPECT_LT((GETTER).asUInt(), (STRINGTABLE).size());                     \
+      EXPECT_EQ_JSON((STRINGTABLE)[(GETTER).asUInt()], String, (STRING));     \
+    }                                                                         \
+  } while (false)
+
+#define EXPECT_JSON_ARRAY_CONTAINS(GETTER, TYPE, VALUE)                       \
+  do {                                                                        \
+    if ((GETTER).isNull()) {                                                  \
+      EXPECT_FALSE((GETTER).isNull()) << #GETTER " doesn't exist or is null"; \
+    } else if (!(GETTER).isArray()) {                                         \
+      EXPECT_TRUE((GETTER).is##TYPE()) << #GETTER " is not an array";         \
+    } else if (const Json::ArrayIndex size = (GETTER).size(); size == 0u) {   \
+      EXPECT_NE(size, 0u) << #GETTER " is an empty array";                    \
+    } else {                                                                  \
+      bool found = false;                                                     \
+      for (Json::ArrayIndex i = 0; i < size; ++i) {                           \
+        if (!(GETTER)[i].is##TYPE()) {                                        \
+          EXPECT_TRUE((GETTER)[i].is##TYPE())                                 \
+              << #GETTER "[" << i << "] is not " #TYPE;                       \
+          break;                                                              \
+        }                                                                     \
+        if ((GETTER)[i].as##TYPE() == (VALUE)) {                              \
+          found = true;                                                       \
+          break;                                                              \
+        }                                                                     \
+      }                                                                       \
+      EXPECT_TRUE(found) << #GETTER " doesn't contain " #VALUE;               \
+    }                                                                         \
+  } while (false)
+
+// Check that the given process root contains all the expected properties.
+static void JSONRootCheck(const Json::Value& aRoot,
+                          bool aWithMainThread = true) {
+  ASSERT_TRUE(aRoot.isObject());
+
+  EXPECT_HAS_JSON(aRoot["libs"], Array);
+
+  GET_JSON(meta, aRoot["meta"], Object);
+  EXPECT_HAS_JSON(meta["version"], UInt);
+  EXPECT_HAS_JSON(meta["startTime"], Double);
+
+  EXPECT_HAS_JSON(aRoot["pages"], Array);
+
+  EXPECT_HAS_JSON(aRoot["profilerOverhead"], Object);
+
+  GET_JSON(threads, aRoot["threads"], Array);
+  const Json::ArrayIndex threadCount = threads.size();
+  for (Json::ArrayIndex i = 0; i < threadCount; ++i) {
+    GET_JSON(thread, threads[i], Object);
+    EXPECT_HAS_JSON(thread["processType"], String);
+    EXPECT_HAS_JSON(thread["name"], String);
+    EXPECT_HAS_JSON(thread["registerTime"], Double);
+    EXPECT_HAS_JSON(thread["samples"], Object);
+    EXPECT_HAS_JSON(thread["markers"], Object);
+    EXPECT_HAS_JSON(thread["pid"], UInt);
+    EXPECT_HAS_JSON(thread["tid"], UInt);
+    EXPECT_HAS_JSON(thread["stackTable"], Object);
+    EXPECT_HAS_JSON(thread["frameTable"], Object);
+    EXPECT_HAS_JSON(thread["stringTable"], Array);
+  }
+
+  if (aWithMainThread) {
+    ASSERT_GT(threadCount, 0u);
+    GET_JSON(thread0, threads[0], Object);
+    EXPECT_EQ_JSON(thread0["name"], String, "GeckoMain");
+  }
+
+  EXPECT_HAS_JSON(aRoot["pausedRanges"], Array);
+
+  const Json::Value& processes = aRoot["processes"];
+  if (!processes.isNull()) {
+    ASSERT_TRUE(processes.isArray());
+    const Json::ArrayIndex processCount = processes.size();
+    for (Json::ArrayIndex i = 0; i < processCount; ++i) {
+      GET_JSON(process, processes[i], Object);
+      JSONRootCheck(process, aWithMainThread);
+    }
+  }
+}
+
+// Check that various expected top properties are in the JSON, and then call the
+// provided `aJSONCheckFunction` with the JSON root object.
+template <typename JSONCheckFunction>
+void JSONOutputCheck(const char* aOutput,
+                     JSONCheckFunction&& aJSONCheckFunction) {
+  ASSERT_NE(aOutput, nullptr);
+
+  // Extract JSON.
+  Json::Value parsedRoot;
+  Json::CharReaderBuilder builder;
+  const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  ASSERT_TRUE(
+      reader->parse(aOutput, strchr(aOutput, '\0'), &parsedRoot, nullptr));
+
+  JSONRootCheck(parsedRoot);
+
+  std::forward<JSONCheckFunction>(aJSONCheckFunction)(parsedRoot);
+}
+
+typedef Vector<const char*> StrVec;
+
+static void InactiveFeaturesAndParamsCheck() {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeBrowsingContextID;
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::NativeAllocations));
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeBrowsingContextID);
+
+  ASSERT_TRUE(entries == 0);
+  ASSERT_TRUE(duration == Nothing());
+  ASSERT_TRUE(interval == 0);
+  ASSERT_TRUE(features == 0);
+  ASSERT_TRUE(filters.empty());
+  ASSERT_TRUE(activeBrowsingContextID == 0);
+}
+
+static void ActiveParamsCheck(int aEntries, double aInterval,
+                              uint32_t aFeatures, const char** aFilters,
+                              size_t aFiltersLen,
+                              uint64_t aActiveBrowsingContextID,
+                              const Maybe<double>& aDuration = Nothing()) {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeBrowsingContextID;
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeBrowsingContextID);
+
+  ASSERT_TRUE(entries == aEntries);
+  ASSERT_TRUE(duration == aDuration);
+  ASSERT_TRUE(interval == aInterval);
+  ASSERT_TRUE(features == aFeatures);
+  ASSERT_TRUE(filters.length() == aFiltersLen);
+  ASSERT_TRUE(activeBrowsingContextID == aActiveBrowsingContextID);
+  for (size_t i = 0; i < aFiltersLen; i++) {
+    ASSERT_TRUE(strcmp(filters[i], aFilters[i]) == 0);
+  }
+}
+
+TEST(GeckoProfiler, Utilities)
+{
+  // We'll assume that this test runs in the main thread (which should be true
+  // when called from the `main` function).
+  const int mainThreadId = profiler_current_thread_id();
+
+  MOZ_RELEASE_ASSERT(profiler_main_thread_id() == mainThreadId);
+  MOZ_RELEASE_ASSERT(profiler_is_main_thread());
+
+  std::thread testThread([&]() {
+    const int testThreadId = profiler_current_thread_id();
+    MOZ_RELEASE_ASSERT(testThreadId != mainThreadId);
+
+    MOZ_RELEASE_ASSERT(profiler_main_thread_id() != testThreadId);
+    MOZ_RELEASE_ASSERT(!profiler_is_main_thread());
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, FeaturesAndParams)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  // Try a couple of features and filters.
+  {
+    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 100,
+                   Some(PROFILER_DEFAULT_DURATION));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 100,
+                      Some(PROFILER_DEFAULT_DURATION));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try some different features and filters.
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    // Testing with some arbitrary buffer size (as could be provided by
+    // external code), which we convert to the appropriate power of 2.
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    // Profiler::Threads is added because filters has multiple entries.
+    ActiveParamsCheck(PowerOfTwo32(999999).Value(), 3,
+                      features | ProfilerFeature::Threads, filters,
+                      MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try with no duration
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    // Profiler::Threads is added because filters has multiple entries.
+    ActiveParamsCheck(PowerOfTwo32(999999).Value(), 3,
+                      features | ProfilerFeature::Threads, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try all supported features, and filters that match all threads.
+  {
+    uint32_t availableFeatures = profiler_get_available_features();
+    const char* filters[] = {""};
+
+    profiler_start(PowerOfTwo32(88888), 10, availableFeatures, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PowerOfTwo32(88888).Value(), 10, availableFeatures,
+                      filters, MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    // Don't call profiler_stop() here.
+  }
+
+  // Try no features, and filters that match no threads.
+  {
+    uint32_t features = 0;
+    const char* filters[] = {"NoThreadWillMatchThis"};
+
+    // Second profiler_start() call in a row without an intervening
+    // profiler_stop(); this will do an implicit profiler_stop() and restart.
+    profiler_start(PowerOfTwo32(0), 0, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(0.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    // Entries and intervals go to defaults if 0 is specified.
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL,
+                      features | ProfilerFeature::Threads, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+
+    // These calls are no-ops.
+    profiler_stop();
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, EnsureStarted)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+  {
+    // Inactive -> Active
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+  }
+
+  {
+    // Active -> Active with same settings
+
+    Maybe<ProfilerBufferInfo> info0 = profiler_get_buffer_info();
+    ASSERT_TRUE(info0->mRangeEnd > 0);
+
+    // First, write some samples into the buffer.
+    PR_Sleep(PR_MillisecondsToInterval(500));
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+    ASSERT_TRUE(info1->mRangeEnd > info0->mRangeEnd);
+
+    // Call profiler_ensure_started with the same settings as before.
+    // This operation must not clear our buffer!
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+
+    // Check that our position in the buffer stayed the same or advanced, but
+    // not by much, and the range-start after profiler_ensure_started shouldn't
+    // have passed the range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeEnd >= info1->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeEnd - info1->mRangeEnd <
+                info1->mRangeEnd - info0->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeStart < info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Active with *different* settings
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+
+    // Call profiler_ensure_started with a different feature set than the one
+    // it's currently running with. This is supposed to stop and restart the
+    // profiler, thereby discarding the buffer contents.
+    uint32_t differentFeatures = features | ProfilerFeature::Leaf;
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            differentFeatures, filters,
+                            MOZ_ARRAY_LENGTH(filters), 0);
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, differentFeatures, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    // Check the the buffer was cleared, so its range-start should be at/after
+    // its range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeStart >= info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Inactive
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, MultiRegistration)
+{
+  // This whole test only checks that function calls don't crash, they don't
+  // actually verify that threads get profiled or not.
+  char top;
+  profiler_register_thread("Main thread again", &top);
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread, no unreg", &top);
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() { profiler_unregister_thread(); });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread 1st", &top);
+      profiler_unregister_thread();
+      profiler_register_thread("thread 2nd", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread once", &top);
+      profiler_register_thread("thread again", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread to unreg twice", &top);
+      profiler_unregister_thread();
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+}
+
+TEST(GeckoProfiler, DifferentThreads)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  // Control the profiler on a background thread and verify flags on the
+  // main thread.
+  {
+    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() {
+                                 profiler_start(PROFILER_DEFAULT_ENTRIES,
+                                                PROFILER_DEFAULT_INTERVAL,
+                                                features, filters,
+                                                MOZ_ARRAY_LENGTH(filters), 0);
+                               }),
+        NS_DISPATCH_SYNC);
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { profiler_stop(); }),
+        NS_DISPATCH_SYNC);
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Control the profiler on the main thread and verify flags on a
+  // background thread.
+  {
+    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    thread->Dispatch(
+        NS_NewRunnableFunction(
+            "GeckoProfiler_DifferentThreads_Test::TestBody",
+            [&]() {
+              ASSERT_TRUE(profiler_is_active());
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::MainThreadIO));
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::IPCMessages));
+
+              ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                                PROFILER_DEFAULT_INTERVAL, features, filters,
+                                MOZ_ARRAY_LENGTH(filters), 0);
+            }),
+        NS_DISPATCH_SYNC);
+
+    profiler_stop();
+
+    thread->Dispatch(
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { InactiveFeaturesAndParamsCheck(); }),
+        NS_DISPATCH_SYNC);
+  }
+
+  thread->Shutdown();
+}
+
+TEST(GeckoProfiler, GetBacktrace)
+{
+  ASSERT_TRUE(!profiler_get_backtrace());
+
+  {
+    uint32_t features = ProfilerFeature::StackWalk;
+    const char* filters[] = {"GeckoMain"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    // These will be destroyed while the profiler is active.
+    static const int N = 100;
+    {
+      UniqueProfilerBacktrace u[N];
+      for (int i = 0; i < N; i++) {
+        u[i] = profiler_get_backtrace();
+        ASSERT_TRUE(u[i]);
+      }
+    }
+
+    // These will be destroyed after the profiler stops.
+    UniqueProfilerBacktrace u[N];
+    for (int i = 0; i < N; i++) {
+      u[i] = profiler_get_backtrace();
+      ASSERT_TRUE(u[i]);
+    }
+
+    profiler_stop();
+  }
+
+  ASSERT_TRUE(!profiler_get_backtrace());
+}
+
+TEST(GeckoProfiler, Pause)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_paused());
+  ASSERT_TRUE(!profiler_can_accept_markers());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(!profiler_is_paused());
+  ASSERT_TRUE(profiler_can_accept_markers());
+
+  // Check that we are writing samples while not paused.
+  Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  // Check that we are writing markers while not paused.
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Not paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  profiler_pause();
+
+  ASSERT_TRUE(profiler_is_paused());
+  ASSERT_TRUE(!profiler_can_accept_markers());
+
+  // Check that we are not writing samples while paused.
+  info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+
+  // Check that we are now writing markers while paused.
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+  PROFILER_MARKER_UNTYPED("Paused v2", OTHER, {});
+  Maybe<ProfilerBufferInfo> info3 = profiler_get_buffer_info();
+  ASSERT_TRUE(info2->mRangeEnd == info3->mRangeEnd);
+
+  profiler_resume();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  ASSERT_TRUE(profiler_can_accept_markers());
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  ASSERT_TRUE(!profiler_can_accept_markers());
+}
+
+TEST(GeckoProfiler, Markers)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  PROFILER_MARKER("tracing event", OTHER, {}, Tracing, "A");
+  PROFILER_MARKER("tracing start", OTHER, MarkerTiming::IntervalStart(),
+                  Tracing, "A");
+  PROFILER_MARKER("tracing end", OTHER, MarkerTiming::IntervalEnd(), Tracing,
+                  "A");
+
+  auto bt = profiler_capture_backtrace();
+  PROFILER_MARKER("tracing event with stack", OTHER,
+                  MarkerStack::TakeBacktrace(std::move(bt)), Tracing, "B");
+
+  { AUTO_PROFILER_TRACING_MARKER("C", "auto tracing", OTHER); }
+
+  PROFILER_MARKER_UNTYPED("M1", OTHER, {});
+  PROFILER_MARKER_UNTYPED("M3", OTHER, {});
+
+  // Create three strings: two that are the maximum allowed length, and one that
+  // is one char longer.
+  static const size_t kMax = ProfileBuffer::kMaxFrameKeyLength;
+  UniquePtr<char[]> okstr1 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> okstr2 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> longstr = MakeUnique<char[]>(kMax + 1);
+  UniquePtr<char[]> longstrCut = MakeUnique<char[]>(kMax + 1);
+  for (size_t i = 0; i < kMax; i++) {
+    okstr1[i] = 'a';
+    okstr2[i] = 'b';
+    longstr[i] = 'c';
+    longstrCut[i] = 'c';
+  }
+  okstr1[kMax - 1] = '\0';
+  okstr2[kMax - 1] = '\0';
+  longstr[kMax] = '\0';
+  longstrCut[kMax] = '\0';
+  // Should be output as-is.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, "");
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, okstr1.get());
+  // Should be output as label + space + okstr2.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("okstr2", LAYOUT, okstr2.get());
+  // Should be output with kMax length, ending with "...\0".
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, longstr.get());
+  ASSERT_EQ(longstrCut[kMax - 4], 'c');
+  longstrCut[kMax - 4] = '.';
+  ASSERT_EQ(longstrCut[kMax - 3], 'c');
+  longstrCut[kMax - 3] = '.';
+  ASSERT_EQ(longstrCut[kMax - 2], 'c');
+  longstrCut[kMax - 2] = '.';
+  ASSERT_EQ(longstrCut[kMax - 1], 'c');
+  longstrCut[kMax - 1] = '\0';
+
+  // Test basic markers 2.0.
+  MOZ_RELEASE_ASSERT(
+      profiler_add_marker("default-templated markers 2.0 with empty options",
+                          geckoprofiler::category::OTHER, {}));
+
+  PROFILER_MARKER_UNTYPED(
+      "default-templated markers 2.0 with option", OTHER,
+      MarkerStack::TakeBacktrace(profiler_capture_backtrace()));
+
+  PROFILER_MARKER("explicitly-default-templated markers 2.0 with empty options",
+                  OTHER, {}, NoPayload);
+
+  MOZ_RELEASE_ASSERT(profiler_add_marker(
+      "explicitly-default-templated markers 2.0 with option",
+      geckoprofiler::category::OTHER, {},
+      ::geckoprofiler::markers::NoPayload{}));
+
+  // Used in markers below.
+  TimeStamp ts1 = TimeStamp::NowUnfuzzed();
+
+  // Sleep briefly to ensure a sample is taken and the pending markers are
+  // processed.
+  PR_Sleep(PR_MillisecondsToInterval(500));
+
+  // Used in markers below.
+  TimeStamp ts2 = TimeStamp::NowUnfuzzed();
+  // ts1 and ts2 should be different thanks to the sleep.
+  EXPECT_NE(ts1, ts2);
+
+  // Test most marker payloads.
+
+  // Keep this one first! (It's used to record `ts1` and `ts2`, to compare
+  // to serialized numbers in other markers.)
+  MOZ_RELEASE_ASSERT(profiler_add_marker(
+      "FirstMarker", geckoprofiler::category::OTHER,
+      MarkerTiming::Interval(ts1, ts2), geckoprofiler::markers::TextMarker{},
+      "First Marker"));
+
+  // User-defined marker type with different properties, and fake schema.
+  struct GtestMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter, int aInt,
+        double aDouble, const mozilla::ProfilerString8View& aText,
+        const mozilla::ProfilerString8View& aUniqueText,
+        const mozilla::TimeStamp& aTime) {
+      aWriter.NullProperty("null");
+      aWriter.BoolProperty("bool-false", false);
+      aWriter.BoolProperty("bool-true", true);
+      aWriter.IntProperty("int", aInt);
+      aWriter.DoubleProperty("double", aDouble);
+      aWriter.StringProperty("text", aText);
+      aWriter.UniqueStringProperty("unique text", aUniqueText);
+      aWriter.UniqueStringProperty("unique text again", aUniqueText);
+      aWriter.TimeProperty("time", aTime);
+    }
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      // Note: This is an test function that is not intended to actually output
+      // that correctly matches StreamJSONMarkerData data above! Instead we only
+      // test that it outputs the expected JSON at the end.
+      using MS = mozilla::MarkerSchema;
+      MS schema{MS::Location::markerChart,      MS::Location::markerTable,
+                MS::Location::timelineOverview, MS::Location::timelineMemory,
+                MS::Location::timelineIPC,      MS::Location::timelineFileIO,
+                MS::Location::stackChart};
+      // All label functions.
+      schema.SetChartLabel("chart label");
+      schema.SetTooltipLabel("tooltip label");
+      schema.SetTableLabel("table label");
+      // All data functions, all formats, all "searchable" values.
+      schema.AddKeyFormat("key with url", MS::Format::url);
+      schema.AddKeyLabelFormat("key with label filePath", "label filePath",
+                               MS::Format::filePath);
+      schema.AddKeyFormatSearchable("key with string not-searchable",
+                                    MS::Format::string,
+                                    MS::Searchable::notSearchable);
+      schema.AddKeyLabelFormatSearchable("key with label duration searchable",
+                                         "label duration", MS::Format::duration,
+                                         MS::Searchable::searchable);
+      schema.AddKeyFormat("key with time", MS::Format::time);
+      schema.AddKeyFormat("key with seconds", MS::Format::seconds);
+      schema.AddKeyFormat("key with milliseconds", MS::Format::milliseconds);
+      schema.AddKeyFormat("key with microseconds", MS::Format::microseconds);
+      schema.AddKeyFormat("key with nanoseconds", MS::Format::nanoseconds);
+      schema.AddKeyFormat("key with bytes", MS::Format::bytes);
+      schema.AddKeyFormat("key with percentage", MS::Format::percentage);
+      schema.AddKeyFormat("key with integer", MS::Format::integer);
+      schema.AddKeyFormat("key with decimal", MS::Format::decimal);
+      schema.AddStaticLabelValue("static label", "static value");
+      return schema;
+    }
+  };
+  MOZ_RELEASE_ASSERT(
+      profiler_add_marker("Gtest custom marker", geckoprofiler::category::OTHER,
+                          MarkerTiming::Interval(ts1, ts2), GtestMarker{}, 42,
+                          43.0, "gtest text", "gtest unique text", ts1));
+
+  // User-defined marker type with no data, special frontend schema.
+  struct GtestSpecialMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-special");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+  MOZ_RELEASE_ASSERT(profiler_add_marker("Gtest special marker",
+                                         geckoprofiler::category::OTHER, {},
+                                         GtestSpecialMarker{}));
+
+  // User-defined marker type that is never used, so it shouldn't appear in the
+  // output.
+  struct GtestUnusedMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-unused");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+
+  // Make sure the compiler doesn't complain about this unused struct.
+  mozilla::Unused << GtestUnusedMarker{};
+
+  // Other markers in alphabetical order of payload class names.
+
+  nsCOMPtr<nsIURI> uri;
+  ASSERT_TRUE(
+      NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), "http://mozilla.org/"_ns)));
+  // The marker name will be "Load <aChannelId>: <aURI>".
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 1,
+      /* NetworkLoadType aType */ NetworkLoadType::LOAD_START,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheHit,
+      /* uint64_t aInnerWindowID */ 78
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */
+      /* nsIURI* aRedirectURI = nullptr */
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 12,
+      /* NetworkLoadType aType */ NetworkLoadType::LOAD_STOP,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* nsIURI* aRedirectURI = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      Some(nsDependentCString("text/html")));
+
+  nsCOMPtr<nsIURI> redirectURI;
+  ASSERT_TRUE(NS_SUCCEEDED(
+      NS_NewURI(getter_AddRefs(redirectURI), "http://example.com/"_ns)));
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 123,
+      /* NetworkLoadType aType */ NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */);
+
+  MOZ_RELEASE_ASSERT(profiler_add_marker(
+      "Text in main thread with stack", geckoprofiler::category::OTHER,
+      {MarkerStack::Capture(), MarkerTiming::Interval(ts1, ts2)},
+      geckoprofiler::markers::TextMarker{}, ""));
+  MOZ_RELEASE_ASSERT(profiler_add_marker(
+      "Text from main thread with stack", geckoprofiler::category::OTHER,
+      MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+      geckoprofiler::markers::TextMarker{}, ""));
+
+  std::thread registeredThread([]() {
+    AUTO_PROFILER_REGISTER_THREAD("Marker test sub-thread");
+    // Marker in non-profiled thread won't be stored.
+    MOZ_RELEASE_ASSERT(profiler_add_marker(
+        "Text in registered thread with stack", geckoprofiler::category::OTHER,
+        MarkerStack::Capture(), geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, with stack from registered thread.
+    MOZ_RELEASE_ASSERT(profiler_add_marker(
+        "Text from registered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  registeredThread.join();
+
+  std::thread unregisteredThread([]() {
+    // Marker in unregistered thread won't be stored.
+    MOZ_RELEASE_ASSERT(profiler_add_marker(
+        "Text in unregistered thread with stack",
+        geckoprofiler::category::OTHER, MarkerStack::Capture(),
+        geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, but stack cannot be captured in an
+    // unregistered thread.
+    MOZ_RELEASE_ASSERT(profiler_add_marker(
+        "Text from unregistered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  unregisteredThread.join();
+
+  MOZ_RELEASE_ASSERT(
+      profiler_add_marker("Tracing", geckoprofiler::category::OTHER, {},
+                          geckoprofiler::markers::Tracing{}, "category"));
+
+  MOZ_RELEASE_ASSERT(
+      profiler_add_marker("Text", geckoprofiler::category::OTHER, {},
+                          geckoprofiler::markers::TextMarker{}, "Text text"));
+
+  MOZ_RELEASE_ASSERT(profiler_add_marker(
+      "MediaSample", geckoprofiler::category::OTHER, {},
+      geckoprofiler::markers::MediaSampleMarker{}, 123, 456));
+
+  SpliceableChunkedJSONWriter w;
+  w.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w));
+  w.End();
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile.get());
+
+  // Expected markers, in order.
+  enum State {
+    S_tracing_event,
+    S_tracing_start,
+    S_tracing_end,
+    S_tracing_event_with_stack,
+    S_tracing_auto_tracing_start,
+    S_tracing_auto_tracing_end,
+    S_M1,
+    S_M3,
+    S_Markers2DefaultEmptyOptions,
+    S_Markers2DefaultWithOptions,
+    S_Markers2ExplicitDefaultEmptyOptions,
+    S_Markers2ExplicitDefaultWithOptions,
+    S_FirstMarker,
+    S_CustomMarker,
+    S_SpecialMarker,
+    S_NetworkMarkerPayload_start,
+    S_NetworkMarkerPayload_stop,
+    S_NetworkMarkerPayload_redirect,
+    S_TextWithStack,
+    S_TextToMTWithStack,
+    S_RegThread_TextToMTWithStack,
+    S_UnregThread_TextToMTWithStack,
+
+    S_LAST,
+  } state = State(0);
+
+  // These will be set when first read from S_FirstMarker, then
+  // compared in following markers.
+  // TODO: Compute these values from the timestamps.
+  double ts1Double = 0.0;
+  double ts2Double = 0.0;
+
+  JSONOutputCheck(profile.get(), [&](const Json::Value& root) {
+    {
+      GET_JSON(threads, root["threads"], Array);
+      ASSERT_EQ(threads.size(), 1u);
+
+      {
+        GET_JSON(thread0, threads[0], Object);
+
+        // Keep a reference to the string table in this block, it will be used
+        // below.
+        GET_JSON(stringTable, thread0["stringTable"], Array);
+        ASSERT_TRUE(stringTable.isArray());
+
+        // Test the expected labels in the string table.
+        bool foundEmpty = false;
+        bool foundOkstr1 = false;
+        bool foundOkstr2 = false;
+        const std::string okstr2Label = std::string("okstr2 ") + okstr2.get();
+        bool foundTooLong = false;
+        for (const auto& s : stringTable) {
+          ASSERT_TRUE(s.isString());
+          std::string sString = s.asString();
+          if (sString.empty()) {
+            EXPECT_FALSE(foundEmpty);
+            foundEmpty = true;
+          } else if (sString == okstr1.get()) {
+            EXPECT_FALSE(foundOkstr1);
+            foundOkstr1 = true;
+          } else if (sString == okstr2Label) {
+            EXPECT_FALSE(foundOkstr2);
+            foundOkstr2 = true;
+          } else if (sString == longstrCut.get()) {
+            EXPECT_FALSE(foundTooLong);
+            foundTooLong = true;
+          } else {
+            EXPECT_NE(sString, longstr.get());
+          }
+        }
+        EXPECT_TRUE(foundEmpty);
+        EXPECT_TRUE(foundOkstr1);
+        EXPECT_TRUE(foundOkstr2);
+        EXPECT_TRUE(foundTooLong);
+
+        {
+          GET_JSON(markers, thread0["markers"], Object);
+
+          {
+            GET_JSON(data, markers["data"], Array);
+
+            for (const Json::Value& marker : data) {
+              // Name the indexes into the marker tuple:
+              // [name, startTime, endTime, phase, category, payload]
+              const unsigned int NAME = 0u;
+              const unsigned int START_TIME = 1u;
+              const unsigned int END_TIME = 2u;
+              const unsigned int PHASE = 3u;
+              const unsigned int CATEGORY = 4u;
+              const unsigned int PAYLOAD = 5u;
+
+              const unsigned int PHASE_INSTANT = 0;
+              const unsigned int PHASE_INTERVAL = 1;
+              const unsigned int PHASE_START = 2;
+              const unsigned int PHASE_END = 3;
+
+              const unsigned int SIZE_WITHOUT_PAYLOAD = 5u;
+              const unsigned int SIZE_WITH_PAYLOAD = 6u;
+
+              ASSERT_TRUE(marker.isArray());
+              // The payload is optional.
+              ASSERT_GE(marker.size(), SIZE_WITHOUT_PAYLOAD);
+              ASSERT_LE(marker.size(), SIZE_WITH_PAYLOAD);
+
+              // root.threads[0].markers.data[i] is an array with 5 or 6
+              // elements.
+
+              ASSERT_TRUE(marker[NAME].isUInt());  // name id
+              GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+              std::string nameString = name.asString();
+
+              EXPECT_TRUE(marker[START_TIME].isNumeric());
+              EXPECT_TRUE(marker[END_TIME].isNumeric());
+              EXPECT_TRUE(marker[PHASE].isUInt());
+              EXPECT_TRUE(marker[PHASE].asUInt() < 4);
+              EXPECT_TRUE(marker[CATEGORY].isUInt());
+
+#define EXPECT_TIMING_INSTANT                  \
+  EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#define EXPECT_TIMING_INTERVAL                 \
+  EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+  EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#define EXPECT_TIMING_START                    \
+  EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#define EXPECT_TIMING_END                      \
+  EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+  EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+#define EXPECT_TIMING_INSTANT_AT(t)            \
+  EXPECT_EQ(marker[START_TIME].asDouble(), t); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#define EXPECT_TIMING_INTERVAL_AT(start, end)      \
+  EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), end);     \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#define EXPECT_TIMING_START_AT(start)              \
+  EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), 0);       \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#define EXPECT_TIMING_END_AT(end)              \
+  EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+  EXPECT_EQ(marker[END_TIME].asDouble(), end); \
+  EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+              if (marker.size() == SIZE_WITHOUT_PAYLOAD) {
+                // root.threads[0].markers.data[i] is an array with 5 elements,
+                // so there is no payload.
+                if (nameString == "M1") {
+                  ASSERT_EQ(state, S_M1);
+                  state = State(state + 1);
+                } else if (nameString == "M3") {
+                  ASSERT_EQ(state, S_M3);
+                  state = State(state + 1);
+                } else if (nameString ==
+                           "default-templated markers 2.0 with empty options") {
+                  EXPECT_EQ(state, S_Markers2DefaultEmptyOptions);
+                  state = State(S_Markers2DefaultEmptyOptions + 1);
+// TODO: Re-enable this when bug 1646714 lands, and check for stack.
+#if 0
+              } else if (nameString ==
+                         "default-templated markers 2.0 with option") {
+                EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                state = State(S_Markers2DefaultWithOptions + 1);
+#endif
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "empty "
+                           "options") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultEmptyOptions);
+                  state = State(S_Markers2ExplicitDefaultEmptyOptions + 1);
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "option") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultWithOptions);
+                  state = State(S_Markers2ExplicitDefaultWithOptions + 1);
+                }
+              } else {
+                // root.threads[0].markers.data[i] is an array with 6 elements,
+                // so there is a payload.
+                GET_JSON(payload, marker[PAYLOAD], Object);
+
+                // root.threads[0].markers.data[i][PAYLOAD] is an object
+                // (payload).
+
+                // It should at least have a "type" string.
+                GET_JSON(type, payload["type"], String);
+                std::string typeString = type.asString();
+
+                if (nameString == "tracing event") {
+                  EXPECT_EQ(state, S_tracing_event);
+                  state = State(S_tracing_event + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing start") {
+                  EXPECT_EQ(state, S_tracing_start);
+                  state = State(S_tracing_start + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_START;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing end") {
+                  EXPECT_EQ(state, S_tracing_end);
+                  state = State(S_tracing_end + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_END;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing event with stack") {
+                  EXPECT_EQ(state, S_tracing_event_with_stack);
+                  state = State(S_tracing_event_with_stack + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "B");
+                  EXPECT_TRUE(payload["stack"].isObject());
+
+                } else if (nameString == "auto tracing") {
+                  switch (state) {
+                    case S_tracing_auto_tracing_start:
+                      state = State(S_tracing_auto_tracing_start + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_START;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      EXPECT_TRUE(payload["stack"].isNull());
+                      break;
+                    case S_tracing_auto_tracing_end:
+                      state = State(S_tracing_auto_tracing_end + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_END;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      ASSERT_TRUE(payload["stack"].isNull());
+                      break;
+                    default:
+                      EXPECT_TRUE(state == S_tracing_auto_tracing_start ||
+                                  state == S_tracing_auto_tracing_end);
+                      break;
+                  }
+
+                } else if (nameString ==
+                           "default-templated markers 2.0 with option") {
+                  // TODO: Remove this when bug 1646714 lands.
+                  EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                  state = State(S_Markers2DefaultWithOptions + 1);
+                  EXPECT_EQ(typeString, "NoPayloadUserData");
+                  EXPECT_FALSE(payload["stack"].isNull());
+
+                } else if (nameString == "FirstMarker") {
+                  // Record start and end times, to compare with timestamps in
+                  // following markers.
+                  EXPECT_EQ(state, S_FirstMarker);
+                  ts1Double = marker[START_TIME].asDouble();
+                  ts2Double = marker[END_TIME].asDouble();
+                  state = State(S_FirstMarker + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_EQ_JSON(payload["name"], String, "First Marker");
+
+                } else if (nameString == "Gtest custom marker") {
+                  EXPECT_EQ(state, S_CustomMarker);
+                  state = State(S_CustomMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest");
+                  EXPECT_EQ(payload.size(), 1u + 9u);
+                  EXPECT_TRUE(payload["null"].isNull());
+                  EXPECT_EQ_JSON(payload["bool-false"], Bool, false);
+                  EXPECT_EQ_JSON(payload["bool-true"], Bool, true);
+                  EXPECT_EQ_JSON(payload["int"], Int64, 42);
+                  EXPECT_EQ_JSON(payload["double"], Double, 43.0);
+                  EXPECT_EQ_JSON(payload["text"], String, "gtest text");
+                  // Unique strings can be fetched from the string table.
+                  ASSERT_TRUE(payload["unique text"].isUInt());
+                  auto textIndex = payload["unique text"].asUInt();
+                  GET_JSON(uniqueText, stringTable[textIndex], String);
+                  ASSERT_TRUE(uniqueText.isString());
+                  ASSERT_EQ(uniqueText.asString(), "gtest unique text");
+                  // The duplicate unique text should have the exact same index.
+                  EXPECT_EQ_JSON(payload["unique text again"], UInt, textIndex);
+                  EXPECT_EQ_JSON(payload["time"], Double, ts1Double);
+
+                } else if (nameString == "Gtest special marker") {
+                  EXPECT_EQ(state, S_SpecialMarker);
+                  state = State(S_SpecialMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest-special");
+                  EXPECT_EQ(payload.size(), 1u) << "Only 'type' in the payload";
+
+                } else if (nameString == "Load 1: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_start);
+                  state = State(S_NetworkMarkerPayload_start + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 1);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Hit");
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 12: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_stop);
+                  state = State(S_NetworkMarkerPayload_stop + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 12);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_EQ_JSON(payload["contentType"], String, "text/html");
+
+                } else if (nameString == "Load 123: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect);
+                  state = State(S_NetworkMarkerPayload_redirect + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 123);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Text in main thread with stack") {
+                  EXPECT_EQ(state, S_TextWithStack);
+                  state = State(S_TextWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_TIMING_INTERVAL_AT(ts1Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString == "Text from main thread with stack") {
+                  EXPECT_EQ(state, S_TextToMTWithStack);
+                  state = State(S_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in registered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in registered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from registered thread with stack") {
+                  EXPECT_EQ(state, S_RegThread_TextToMTWithStack);
+                  state = State(S_RegThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in unregistered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in unregistered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from unregistered thread with stack") {
+                  EXPECT_EQ(state, S_UnregThread_TextToMTWithStack);
+                  state = State(S_UnregThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_TRUE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+                }
+              }  // marker with payload
+            }    // for (marker : data)
+          }      // markers.data
+        }        // markers
+      }          // thread0
+    }            // threads
+    // We should have read all expected markers.
+    EXPECT_EQ(state, S_LAST);
+
+    {
+      GET_JSON(meta, root["meta"], Object);
+
+      {
+        GET_JSON(markerSchema, meta["markerSchema"], Array);
+
+        std::set<std::string> testedSchemaNames;
+
+        for (const Json::Value& schema : markerSchema) {
+          GET_JSON(name, schema["name"], String);
+          const std::string nameString = name.asString();
+
+          GET_JSON(display, schema["display"], Array);
+
+          GET_JSON(data, schema["data"], Array);
+
+          EXPECT_TRUE(
+              testedSchemaNames
+                  .insert(std::string(nameString.data(), nameString.size()))
+                  .second)
+              << "Each schema name should be unique (inserted once in the set)";
+
+          if (nameString == "Text") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Details");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "NoPayloadUserData") {
+            // TODO: Remove this when bug 1646714 lands.
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "FileIO") {
+            // These are defined in ProfilerIOInterposeObserver.cpp
+
+          } else if (nameString == "tracing") {
+            EXPECT_EQ(display.size(), 3u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "BHR-detected hang") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "MainThreadLongTask") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "Log") {
+            EXPECT_EQ(display.size(), 1u);
+            EXPECT_EQ(display[0u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "module");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Module");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Name");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "string");
+
+          } else if (nameString == "MediaSample") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "sampleStartTimeUs");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Sample start time");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "sampleEndTimeUs");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Sample end time");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "microseconds");
+
+          } else if (nameString == "Budget") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest") {
+            EXPECT_EQ(display.size(), 7u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+            EXPECT_EQ(display[3u].asString(), "timeline-memory");
+            EXPECT_EQ(display[4u].asString(), "timeline-ipc");
+            EXPECT_EQ(display[5u].asString(), "timeline-fileio");
+            EXPECT_EQ(display[6u].asString(), "stack-chart");
+
+            EXPECT_EQ_JSON(schema["chartLabel"], String, "chart label");
+            EXPECT_EQ_JSON(schema["tooltipLabel"], String, "tooltip label");
+            EXPECT_EQ_JSON(schema["tableLabel"], String, "table label");
+
+            ASSERT_EQ(data.size(), 14u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "key with url");
+            EXPECT_TRUE(data[0u]["label"].isNull());
+            EXPECT_EQ_JSON(data[0u]["format"], String, "url");
+            EXPECT_TRUE(data[0u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "key with label filePath");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "label filePath");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "file-path");
+            EXPECT_TRUE(data[1u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[2u].isObject());
+            EXPECT_EQ_JSON(data[2u]["key"], String,
+                           "key with string not-searchable");
+            EXPECT_TRUE(data[2u]["label"].isNull());
+            EXPECT_EQ_JSON(data[2u]["format"], String, "string");
+            EXPECT_EQ_JSON(data[2u]["searchable"], Bool, false);
+
+            ASSERT_TRUE(data[3u].isObject());
+            EXPECT_EQ_JSON(data[3u]["key"], String,
+                           "key with label duration searchable");
+            EXPECT_TRUE(data[3u]["label duration"].isNull());
+            EXPECT_EQ_JSON(data[3u]["format"], String, "duration");
+            EXPECT_EQ_JSON(data[3u]["searchable"], Bool, true);
+
+            ASSERT_TRUE(data[4u].isObject());
+            EXPECT_EQ_JSON(data[4u]["key"], String, "key with time");
+            EXPECT_TRUE(data[4u]["label"].isNull());
+            EXPECT_EQ_JSON(data[4u]["format"], String, "time");
+            EXPECT_TRUE(data[4u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[5u].isObject());
+            EXPECT_EQ_JSON(data[5u]["key"], String, "key with seconds");
+            EXPECT_TRUE(data[5u]["label"].isNull());
+            EXPECT_EQ_JSON(data[5u]["format"], String, "seconds");
+            EXPECT_TRUE(data[5u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[6u].isObject());
+            EXPECT_EQ_JSON(data[6u]["key"], String, "key with milliseconds");
+            EXPECT_TRUE(data[6u]["label"].isNull());
+            EXPECT_EQ_JSON(data[6u]["format"], String, "milliseconds");
+            EXPECT_TRUE(data[6u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[7u].isObject());
+            EXPECT_EQ_JSON(data[7u]["key"], String, "key with microseconds");
+            EXPECT_TRUE(data[7u]["label"].isNull());
+            EXPECT_EQ_JSON(data[7u]["format"], String, "microseconds");
+            EXPECT_TRUE(data[7u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[8u].isObject());
+            EXPECT_EQ_JSON(data[8u]["key"], String, "key with nanoseconds");
+            EXPECT_TRUE(data[8u]["label"].isNull());
+            EXPECT_EQ_JSON(data[8u]["format"], String, "nanoseconds");
+            EXPECT_TRUE(data[8u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[9u].isObject());
+            EXPECT_EQ_JSON(data[9u]["key"], String, "key with bytes");
+            EXPECT_TRUE(data[9u]["label"].isNull());
+            EXPECT_EQ_JSON(data[9u]["format"], String, "bytes");
+            EXPECT_TRUE(data[9u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[10u].isObject());
+            EXPECT_EQ_JSON(data[10u]["key"], String, "key with percentage");
+            EXPECT_TRUE(data[10u]["label"].isNull());
+            EXPECT_EQ_JSON(data[10u]["format"], String, "percentage");
+            EXPECT_TRUE(data[10u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[11u].isObject());
+            EXPECT_EQ_JSON(data[11u]["key"], String, "key with integer");
+            EXPECT_TRUE(data[11u]["label"].isNull());
+            EXPECT_EQ_JSON(data[11u]["format"], String, "integer");
+            EXPECT_TRUE(data[11u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[12u].isObject());
+            EXPECT_EQ_JSON(data[12u]["key"], String, "key with decimal");
+            EXPECT_TRUE(data[12u]["label"].isNull());
+            EXPECT_EQ_JSON(data[12u]["format"], String, "decimal");
+            EXPECT_TRUE(data[12u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[13u].isObject());
+            EXPECT_EQ_JSON(data[13u]["label"], String, "static label");
+            EXPECT_EQ_JSON(data[13u]["value"], String, "static value");
+
+          } else if (nameString == "markers-gtest-special") {
+            EXPECT_EQ(display.size(), 0u);
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest-unused") {
+            ADD_FAILURE() << "Schema for GtestUnusedMarker should not be here";
+
+          } else {
+            printf("FYI: Unknown marker schema '%s'\n", nameString.c_str());
+          }
+        }
+
+        // Check that we've got all expected schema.
+        EXPECT_TRUE(testedSchemaNames.find("Text") != testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("tracing") !=
+                    testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("MediaSample") !=
+                    testedSchemaNames.end());
+      }  // markerSchema
+    }    // meta
+  });
+
+  Maybe<ProfilerBufferInfo> info = profiler_get_buffer_info();
+  MOZ_RELEASE_ASSERT(info.isSome());
+  printf("Profiler buffer range: %llu .. %llu (%llu bytes)\n",
+         static_cast<unsigned long long>(info->mRangeStart),
+         static_cast<unsigned long long>(info->mRangeEnd),
+         // sizeof(ProfileBufferEntry) == 9
+         (static_cast<unsigned long long>(info->mRangeEnd) -
+          static_cast<unsigned long long>(info->mRangeStart)) *
+             9);
+  printf("Stats:         min(us) .. mean(us) .. max(us)  [count]\n");
+  printf("- Intervals:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mIntervalsUs.min, info->mIntervalsUs.sum / info->mIntervalsUs.n,
+         info->mIntervalsUs.max, info->mIntervalsUs.n);
+  printf("- Overheads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mOverheadsUs.min, info->mOverheadsUs.sum / info->mOverheadsUs.n,
+         info->mOverheadsUs.max, info->mOverheadsUs.n);
+  printf("  - Locking:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mLockingsUs.min, info->mLockingsUs.sum / info->mLockingsUs.n,
+         info->mLockingsUs.max, info->mLockingsUs.n);
+  printf("  - Clearning: %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCleaningsUs.min, info->mCleaningsUs.sum / info->mCleaningsUs.n,
+         info->mCleaningsUs.max, info->mCleaningsUs.n);
+  printf("  - Counters:  %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCountersUs.min, info->mCountersUs.sum / info->mCountersUs.n,
+         info->mCountersUs.max, info->mCountersUs.n);
+  printf("  - Threads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mThreadsUs.min, info->mThreadsUs.sum / info->mThreadsUs.n,
+         info->mThreadsUs.max, info->mThreadsUs.n);
+
+  profiler_stop();
+
+  // Try to add markers while the profiler is stopped.
+  PROFILER_MARKER_UNTYPED("marker after profiler_stop", OTHER);
+
+  // Warning: this could be racy
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // This last marker shouldn't get streamed.
+  SpliceableChunkedJSONWriter w2;
+  w2.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w2));
+  w2.End();
+  UniquePtr<char[]> profile2 = w.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile2.get());
+  EXPECT_TRUE(
+      std::string_view(profile2.get()).find("marker after profiler_stop") ==
+      std::string_view::npos);
+
+  profiler_stop();
+}
+
+#define COUNTER_NAME "TestCounter"
+#define COUNTER_DESCRIPTION "Test of counters in profiles"
+#define COUNTER_NAME2 "Counter2"
+#define COUNTER_DESCRIPTION2 "Second Test of counters in profiles"
+
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter, COUNTER_NAME, COUNTER_DESCRIPTION);
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter2, COUNTER_NAME2, COUNTER_DESCRIPTION2);
+
+TEST(GeckoProfiler, Counters)
+{
+  uint32_t features = ProfilerFeature::Threads;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+
+  // Inactive -> Active
+  profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                          features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  AUTO_PROFILER_COUNT_TOTAL(TestCounter, 10);
+  PR_Sleep(PR_MillisecondsToInterval(200));
+  AUTO_PROFILER_COUNT_TOTAL(TestCounter, 7);
+  PR_Sleep(PR_MillisecondsToInterval(200));
+  AUTO_PROFILER_COUNT_TOTAL(TestCounter, -17);
+  PR_Sleep(PR_MillisecondsToInterval(200));
+
+  // Verify we got counters in the output
+  SpliceableChunkedJSONWriter w;
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w));
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  // counter name and description should appear as is.
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_NAME));
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_DESCRIPTION));
+  ASSERT_FALSE(strstr(profile.get(), COUNTER_NAME2));
+  ASSERT_FALSE(strstr(profile.get(), COUNTER_DESCRIPTION2));
+
+  AUTO_PROFILER_COUNT_TOTAL(TestCounter2, 10);
+  PR_Sleep(PR_MillisecondsToInterval(200));
+
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w));
+
+  profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_NAME));
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_DESCRIPTION));
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_NAME2));
+  ASSERT_TRUE(strstr(profile.get(), COUNTER_DESCRIPTION2));
+
+  profiler_stop();
+}
+
+TEST(GeckoProfiler, Time)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  double t1 = profiler_time();
+  double t2 = profiler_time();
+  ASSERT_TRUE(t1 <= t2);
+
+  // profiler_start() restarts the timer used by profiler_time().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  double t3 = profiler_time();
+  double t4 = profiler_time();
+  ASSERT_TRUE(t3 <= t4);
+
+  profiler_stop();
+
+  double t5 = profiler_time();
+  double t6 = profiler_time();
+  ASSERT_TRUE(t4 <= t5 && t1 <= t6);
+}
+
+TEST(GeckoProfiler, GetProfile)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_get_profile());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  mozilla::Maybe<uint32_t> activeFeatures = profiler_features_if_active();
+  ASSERT_TRUE(activeFeatures.isSome());
+  // Not all platforms support stack-walking.
+  const bool hasStackWalk = ProfilerFeature::HasStackWalk(*activeFeatures);
+  // "threads" may automatically be added when `filters` is not empty.
+  const bool hasThreads = ProfilerFeature::HasThreads(*activeFeatures);
+
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+    GET_JSON(meta, aRoot["meta"], Object);
+    {
+      GET_JSON(configuration, meta["configuration"], Object);
+      {
+        GET_JSON(features, configuration["features"], Array);
+        {
+          EXPECT_EQ(features.size(),
+                    (hasStackWalk ? 1u : 0u) + (hasThreads ? 1u : 0u));
+          if (hasStackWalk) {
+            EXPECT_JSON_ARRAY_CONTAINS(features, String, "stackwalk");
+          }
+          if (hasThreads) {
+            EXPECT_JSON_ARRAY_CONTAINS(features, String, "threads");
+          }
+        }
+        GET_JSON(threads, configuration["threads"], Array);
+        {
+          EXPECT_EQ(threads.size(), 1u);
+          EXPECT_JSON_ARRAY_CONTAINS(threads, String, "GeckoMain");
+        }
+      }
+    }
+  });
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, StreamJSONForThisProcess)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w;
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  w.Start();
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w));
+  w.End();
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  profiler_stop();
+
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+}
+
+TEST(GeckoProfiler, StreamJSONForThisProcessThreaded)
+{
+  // Same as the previous test, but calling some things on background threads.
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w;
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+
+  // Start the profiler on the main thread.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Call profiler_stream_json_for_this_process on a background thread.
+  thread->Dispatch(
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            w.Start();
+            ASSERT_TRUE(::profiler_stream_json_for_this_process(w));
+            w.End();
+          }),
+      NS_DISPATCH_SYNC);
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  // Stop the profiler and call profiler_stream_json_for_this_process on a
+  // background thread.
+  thread->Dispatch(
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            profiler_stop();
+            ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+          }),
+      NS_DISPATCH_SYNC);
+  thread->Shutdown();
+
+  // Call profiler_stream_json_for_this_process on the main thread.
+  ASSERT_TRUE(!::profiler_stream_json_for_this_process(w));
+}
+
+TEST(GeckoProfiler, ProfilingStack)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  AUTO_PROFILER_LABEL("A::B", OTHER);
+
+  UniqueFreePtr<char> dynamic(strdup("dynamic"));
+  {
+    AUTO_PROFILER_LABEL_DYNAMIC_CSTR("A::C", JS, dynamic.get());
+    AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("A::C2", JS,
+                                          nsDependentCString(dynamic.get()));
+    AUTO_PROFILER_LABEL_DYNAMIC_LOSSY_NSSTRING(
+        "A::C3", JS, NS_ConvertUTF8toUTF16(dynamic.get()));
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_get_backtrace());
+  }
+
+  AutoProfilerLabel label1("A", nullptr, JS::ProfilingCategoryPair::DOM);
+  AutoProfilerLabel label2("A", dynamic.get(),
+                           JS::ProfilingCategoryPair::NETWORK);
+  ASSERT_TRUE(profiler_get_backtrace());
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, Bug1355807)
+{
+  uint32_t features = ProfilerFeature::JS;
+  const char* manyThreadsFilter[] = {""};
+  const char* fewThreadsFilter[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 manyThreadsFilter, MOZ_ARRAY_LENGTH(manyThreadsFilter), 0);
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  // In bug 1355807 this caused an assertion failure in StopJSSampling().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  profiler_stop();
+}
+
+class GTestStackCollector final : public ProfilerStackCollector {
+ public:
+  GTestStackCollector() : mSetIsMainThread(0), mFrames(0) {}
+
+  virtual void SetIsMainThread() { mSetIsMainThread++; }
+
+  virtual void CollectNativeLeafAddr(void* aAddr) { mFrames++; }
+  virtual void CollectJitReturnAddr(void* aAddr) { mFrames++; }
+  virtual void CollectWasmFrame(const char* aLabel) { mFrames++; }
+  virtual void CollectProfilingStackFrame(
+      const js::ProfilingStackFrame& aFrame) {
+    mFrames++;
+  }
+
+  int mSetIsMainThread;
+  int mFrames;
+};
+
+void DoSuspendAndSample(int aTid, nsIThread* aThread) {
+  aThread->Dispatch(
+      NS_NewRunnableFunction("GeckoProfiler_SuspendAndSample_Test::TestBody",
+                             [&]() {
+                               uint32_t features = ProfilerFeature::Leaf;
+                               GTestStackCollector collector;
+                               profiler_suspend_and_sample_thread(
+                                   aTid, features, collector,
+                                   /* sampleNative = */ true);
+
+                               ASSERT_TRUE(collector.mSetIsMainThread == 1);
+                               ASSERT_TRUE(collector.mFrames > 0);
+                             }),
+      NS_DISPATCH_SYNC);
+}
+
+TEST(GeckoProfiler, SuspendAndSample)
+{
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_TRUE(NS_SUCCEEDED(rv));
+
+  int tid = profiler_current_thread_id();
+
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Suspend and sample while the profiler is inactive.
+  DoSuspendAndSample(tid, thread);
+
+  uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(profiler_is_active());
+
+  // Suspend and sample while the profiler is active.
+  DoSuspendAndSample(tid, thread);
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_active());
+}
+
+// Returns `static_cast<SamplingState>(-1)` if callback could not be installed.
+static SamplingState WaitForSamplingState() {
+  Atomic<int> samplingState{-1};
+
+  if (!profiler_callback_after_sampling([&](SamplingState aSamplingState) {
+        samplingState = static_cast<int>(aSamplingState);
+      })) {
+    return static_cast<SamplingState>(-1);
+  }
+
+  while (samplingState == -1) {
+  }
+
+  return static_cast<SamplingState>(static_cast<int>(samplingState));
+}
+
+TEST(GeckoProfiler, PostSamplingCallback)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileCompleted = profiler_get_profile();
+  JSONOutputCheck(profileCompleted.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback completed");
+      }
+    }
+  });
+
+  profiler_pause();
+  {
+    // Paused -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback paused", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingPaused);
+  }
+  UniquePtr<char[]> profilePaused = profiler_get_profile();
+  JSONOutputCheck(profilePaused.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profilePaused.get(), "PostSamplingCallback paused"));
+
+  profiler_resume();
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback resumed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileResumed = profiler_get_profile();
+  JSONOutputCheck(profileResumed.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback resumed");
+      }
+    }
+  });
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::NoStackSampling,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  {
+    // No stack sampling -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed (no stacks)", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::NoStackSamplingCompleted);
+  }
+  UniquePtr<char[]> profileNoStacks = profiler_get_profile();
+  JSONOutputCheck(profileNoStacks.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profileNoStacks.get(),
+                      "PostSamplingCallback completed (no stacks)"));
+
+  // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+  // it would require coordination between `profiler_stop()` and another thread
+  // doing `profiler_callback_after_sampling()` at just the right moment.
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+}
+
+TEST(GeckoProfiler, BaseProfilerHandOff)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Start the Base Profiler.
+  baseprofiler::profiler_start(
+      PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+      ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters));
+
+  ASSERT_TRUE(baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Add at least a marker, which should go straight into the buffer.
+  Maybe<baseprofiler::ProfilerBufferInfo> info0 =
+      baseprofiler::profiler_get_buffer_info();
+  BASE_PROFILER_MARKER_UNTYPED("Marker from base profiler", OTHER, {});
+  Maybe<baseprofiler::ProfilerBufferInfo> info1 =
+      baseprofiler::profiler_get_buffer_info();
+  ASSERT_GT(info1->mRangeEnd, info0->mRangeEnd);
+
+  // Start the Gecko Profiler, which should grab the Base Profiler profile and
+  // stop it.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(profiler_is_active());
+
+  // Write some Gecko Profiler samples.
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+  // Check that the Gecko Profiler profile contains at least the Base Profiler
+  // main thread samples.
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      bool found = false;
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain (pre-xul)") {
+          found = true;
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Marker from base profiler");
+          break;
+        }
+      }
+      EXPECT_TRUE(found);
+    }
+  });
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+}
+
+TEST(GeckoProfiler, CPUUsage)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  // Grab a few samples.
+  static constexpr unsigned MinSamplings = 10;
+  for (unsigned i = MinSamplings; i != 0; --i) {
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {
+    // Check that the "cpu" feature is present.
+    GET_JSON(meta, aRoot["meta"], Object);
+    {
+      GET_JSON(configuration, meta["configuration"], Object);
+      {
+        GET_JSON(features, configuration["features"], Array);
+        { EXPECT_JSON_ARRAY_CONTAINS(features, String, "cpu"); }
+      }
+    }
+
+    {
+      GET_JSON(sampleUnits, meta["sampleUnits"], Object);
+      {
+        EXPECT_EQ_JSON(sampleUnits["time"], String, "ms");
+        EXPECT_EQ_JSON(sampleUnits["eventDelay"], String, "ms");
+#if defined(GP_OS_windows) || defined(GP_OS_darwin) || defined(GP_OS_linux) || \
+    defined(GP_OS_android) || defined(GP_OS_freebsd)
+        // Note: The exact string is not important here.
+        EXPECT_TRUE(sampleUnits["threadCPUDelta"].isString())
+            << "There should be a sampleUnits.threadCPUDelta on this platform";
+#else
+        EXPECT_FALSE(sampleUnits.isMember("threadCPUDelta"))
+            << "Unexpected sampleUnits.threadCPUDelta on this platform";;
+#endif
+      }
+    }
+
+    // Check that the sample schema contains "threadCPUDelta".
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        GET_JSON(samples, thread0["samples"], Object);
+        {
+          Json::ArrayIndex threadCPUDeltaIndex = 0;
+          GET_JSON(schema, samples["schema"], Object);
+          {
+            GET_JSON(index, schema["threadCPUDelta"], UInt);
+            threadCPUDeltaIndex = index.asUInt();
+          }
+
+          unsigned threadCPUDeltaCount = 0;
+          GET_JSON(data, samples["data"], Array);
+          EXPECT_GE(data.size(), MinSamplings);
+          for (const Json::Value& sample : data) {
+            ASSERT_TRUE(sample.isArray());
+            if (sample.isValidIndex(threadCPUDeltaIndex)) {
+              if (!sample[threadCPUDeltaIndex].isNull()) {
+                EXPECT_TRUE(sample[threadCPUDeltaIndex].isUInt64());
+                ++threadCPUDeltaCount;
+              }
+            }
+          }
+
+#if defined(GP_OS_windows) || defined(GP_OS_darwin) || defined(GP_OS_linux) || \
+    defined(GP_OS_android) || defined(GP_OS_freebsd)
+          EXPECT_GE(threadCPUDeltaCount, data.size() - 1u)
+              << "There should be 'threadCPUDelta' values in all but 1 samples";
+#else
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(threadCPUDeltaCount, 0u);
+#endif
+        }
+      }
+    }
+  });
+
+  // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+  // it would require coordination between `profiler_stop()` and another thread
+  // doing `profiler_callback_after_sampling()` at just the right moment.
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+}