Revert of Revert of Unflake V8 sampling profiler tests. (patchset #1 id:1 of https://codereview.chromium.org/1017183004/)

Reason for revert:
Suspecting goma flake. Relanding.

Original issue's description:
> Revert of Unflake V8 sampling profiler tests. (patchset #1 id:1 of https://codereview.chromium.org/1032633002/)
>
> Reason for revert:
> Broke compilation on Mac Builder:
> https://build.chromium.org/p/chromium.mac/builders/Mac%20Builder/builds/19512/steps/compile/logs/stdio
>
> when compiling content/renderer/devtools/v8_sampling_profiler_browsertest.cc
>
> Original issue's description:
> > Unflake V8 sampling profiler tests.
> >
> > BUG=406277
> >
> > Committed: https://crrev.com/d6493ce2a4ed6f346a31597ac27748a3429a1d95
> > Cr-Commit-Position: refs/heads/master@{#321970}
>
> TBR=yurys@chromium.org,alph@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=406277
>
> Committed: https://crrev.com/3703085199a63732add21d955c6280765e3c480e
> Cr-Commit-Position: refs/heads/master@{#321975}

TBR=yurys@chromium.org,pneubeck@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=406277

Review URL: https://codereview.chromium.org/1029353002

Cr-Commit-Position: refs/heads/master@{#321977}

3 files changed, 26 insertions, 11 deletions

diff --git a/content/renderer/devtools/v8_sampling_profiler.cc b/content/renderer/devtools/v8_sampling_profiler.cc
index 06d3104..9b32497 100644
--- a/content/renderer/devtools/v8_sampling_profiler.cc
+++ b/content/renderer/devtools/v8_sampling_profiler.cc
@@ -117,9 +117,16 @@ class Sampler {
 
   void DoSample(const v8::RegisterState& state);
 
+  void SetEventsToCollectForTest(int code_added_events, int sample_events) {
+    code_added_events_to_collect_for_test_ = code_added_events;
+    sample_events_to_collect_for_test_ = sample_events;
+  }
+
   bool EventsCollectedForTest() const {
-    return base::subtle::NoBarrier_Load(&code_added_events_count_) != 0 ||
-           base::subtle::NoBarrier_Load(&samples_count_) != 0;
+    return base::subtle::NoBarrier_Load(&code_added_events_count_) >=
+               code_added_events_to_collect_for_test_ &&
+           base::subtle::NoBarrier_Load(&samples_count_) >=
+               sample_events_to_collect_for_test_;
   }
 
  private:
@@ -142,6 +149,8 @@ class Sampler {
   scoped_ptr<SamplingQueue> samples_data_;
   base::subtle::Atomic32 code_added_events_count_;
   base::subtle::Atomic32 samples_count_;
+  int code_added_events_to_collect_for_test_;
+  int sample_events_to_collect_for_test_;
 
   static base::LazyInstance<base::ThreadLocalPointer<Sampler>>::Leaky
       tls_instance_;
@@ -155,7 +164,9 @@ Sampler::Sampler()
       thread_handle_(Sampler::GetCurrentThreadHandle()),
       isolate_(Isolate::GetCurrent()),
       code_added_events_count_(0),
-      samples_count_(0) {
+      samples_count_(0),
+      code_added_events_to_collect_for_test_(0),
+      sample_events_to_collect_for_test_(0) {
   DCHECK(isolate_);
   DCHECK(!GetInstance());
   tls_instance_.Pointer()->Set(this);
@@ -213,7 +224,6 @@ void Sampler::DoSample(const v8::RegisterState& state) {
     return;
   record->Collect(isolate_, timestamp, state);
   samples_data_->FinishEnqueue();
-  base::subtle::NoBarrier_AtomicIncrement(&samples_count_, 1);
 }
 
 void Sampler::InjectPendingEvents() {
@@ -225,6 +235,7 @@ void Sampler::InjectPendingEvents() {
         record->ToTraceFormat());
     samples_data_->Remove();
     record = samples_data_->Peek();
+    base::subtle::NoBarrier_AtomicIncrement(&samples_count_, 1);
   }
 }
 
@@ -548,7 +559,10 @@ void V8SamplingProfiler::OnTraceLogDisabled() {
   sampling_thread_.reset();
 }
 
-void V8SamplingProfiler::EnableSamplingEventForTesting() {
+void V8SamplingProfiler::EnableSamplingEventForTesting(int code_added_events,
+                                                       int sample_events) {
+  render_thread_sampler_->SetEventsToCollectForTest(code_added_events,
+                                                    sample_events);
   waitable_event_for_testing_.reset(new base::WaitableEvent(false, false));
 }
 
diff --git a/content/renderer/devtools/v8_sampling_profiler.h b/content/renderer/devtools/v8_sampling_profiler.h
index 346a46c..5b7d094 100644
--- a/content/renderer/devtools/v8_sampling_profiler.h
+++ b/content/renderer/devtools/v8_sampling_profiler.h
@@ -26,7 +26,7 @@ class CONTENT_EXPORT V8SamplingProfiler final
   void OnTraceLogEnabled() override;
   void OnTraceLogDisabled() override;
 
-  void EnableSamplingEventForTesting();
+  void EnableSamplingEventForTesting(int code_added_events, int sample_events);
   void WaitSamplingEventForTesting();
 
  private:
diff --git a/content/renderer/devtools/v8_sampling_profiler_browsertest.cc b/content/renderer/devtools/v8_sampling_profiler_browsertest.cc
index ba1b0e5..1ccae8c 100644
--- a/content/renderer/devtools/v8_sampling_profiler_browsertest.cc
+++ b/content/renderer/devtools/v8_sampling_profiler_browsertest.cc
@@ -77,9 +77,10 @@ class V8SamplingProfilerTest : public RenderViewTest {
       flush_complete_event->Signal();
   }
 
-  void CollectTrace() {
+  void CollectTrace(int code_added_events, int sample_events) {
     TraceLog* trace_log = TraceLog::GetInstance();
-    sampling_profiler_->EnableSamplingEventForTesting();
+    sampling_profiler_->EnableSamplingEventForTesting(code_added_events,
+                                                      sample_events);
     trace_log->SetEnabled(
         CategoryFilter(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profile")),
         TraceLog::RECORDING_MODE, TraceOptions());
@@ -129,7 +130,7 @@ class V8SamplingProfilerTest : public RenderViewTest {
 #endif
 
 TEST_F(V8SamplingProfilerTest, MAYBE(V8SamplingEventFired)) {
-  sampling_profiler_->EnableSamplingEventForTesting();
+  sampling_profiler_->EnableSamplingEventForTesting(0, 0);
   TraceLog::GetInstance()->SetEnabled(
       CategoryFilter(TRACE_DISABLED_BY_DEFAULT("v8.cpu_profile")),
       TraceLog::RECORDING_MODE, TraceOptions());
@@ -139,14 +140,14 @@ TEST_F(V8SamplingProfilerTest, MAYBE(V8SamplingEventFired)) {
 }
 
 TEST_F(V8SamplingProfilerTest, MAYBE(V8SamplingJitCodeEventsCollected)) {
-  CollectTrace();
+  CollectTrace(1, 0);
   int jit_code_added_events_count = CountEvents("JitCodeAdded");
   CHECK_LT(0, jit_code_added_events_count);
   base::RunLoop().RunUntilIdle();
 }
 
 TEST_F(V8SamplingProfilerTest, MAYBE(V8SamplingSamplesCollected)) {
-  CollectTrace();
+  CollectTrace(0, 1);
   int sample_events_count = CountEvents("V8Sample");
   CHECK_LT(0, sample_events_count);
   base::RunLoop().RunUntilIdle();