commit aa4df68be5bc62cae52afe4f9476ab3fc1328575
author Charlie Andrews <charliea@chromium.org> Thu Apr 18 16:30:59 2019
committer Commit Bot <commit-bot@chromium.org> Thu Apr 18 16:30:59 2019
tree 3e3f1f2c1761d86c637875e6258d2e17599c3935
parent 1bb65c1dc27131513e851786d1c3707a60d43353

Create a process-global MetadataRecorder for the stack sampling profiler

This paves the way for Chromium code to manipulate the metadata
recorder and help provide the stack sampling profiler with context
about what's happening when a sample is taken.

Bug: 913570
Change-Id: I96d7bcc2f4872467852042495c0fdf1ad5d8c4cc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1572370
Commit-Queue: Charlie Andrews <charliea@chromium.org>
Commit-Queue: Mike Wittman <wittman@chromium.org>
Reviewed-by: Mike Wittman <wittman@chromium.org>
Auto-Submit: Charlie Andrews <charliea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652161}

chrome/common/thread_profiler.cc

diff --git a/chrome/common/thread_profiler.cc b/chrome/common/thread_profiler.cc
index db16b3b..ca9b35b 100644
--- a/chrome/common/thread_profiler.cc
+++ b/chrome/common/thread_profiler.cc
@@ -234,7 +234,9 @@
       std::make_unique<CallStackProfileBuilder>(
           CallStackProfileParams(GetProcess(), thread,
                                  CallStackProfileParams::PROCESS_STARTUP),
-          work_id_recorder_.get()));
+          work_id_recorder_.get(),
+          &metrics::CallStackProfileBuilder::
+              GetStackSamplingProfilerMetadataRecorder()));
 
   startup_profiler_->Start();
 
@@ -280,7 +282,9 @@
       std::make_unique<CallStackProfileBuilder>(
           CallStackProfileParams(GetProcess(), thread_,
                                  CallStackProfileParams::PERIODIC_COLLECTION),
-          work_id_recorder_.get(), nullptr,
+          work_id_recorder_.get(),
+          &metrics::CallStackProfileBuilder::
+              GetStackSamplingProfilerMetadataRecorder(),
           base::BindOnce(&ThreadProfiler::OnPeriodicCollectionCompleted,
                          owning_thread_task_runner_,
                          weak_factory_.GetWeakPtr())));

components/metrics/call_stack_profile_builder.cc

diff --git a/components/metrics/call_stack_profile_builder.cc b/components/metrics/call_stack_profile_builder.cc
index 3505f11..2adbe53 100644
--- a/components/metrics/call_stack_profile_builder.cc
+++ b/components/metrics/call_stack_profile_builder.cc
@@ -200,6 +200,13 @@
       std::move(browser_interface));
 }
 
+// static
+MetadataRecorder&
+CallStackProfileBuilder::GetStackSamplingProfilerMetadataRecorder() {
+  static base::NoDestructor<MetadataRecorder> instance;
+  return *instance;
+}
+
 void CallStackProfileBuilder::PassProfilesToMetricsProvider(
     SampledProfile sampled_profile) {
   if (sampled_profile.process() == BROWSER_PROCESS) {

components/metrics/call_stack_profile_builder.h

diff --git a/components/metrics/call_stack_profile_builder.h b/components/metrics/call_stack_profile_builder.h
index 877944c..23341fc 100644
--- a/components/metrics/call_stack_profile_builder.h
+++ b/components/metrics/call_stack_profile_builder.h
@@ -81,6 +81,10 @@
   static void SetParentProfileCollectorForChildProcess(
       metrics::mojom::CallStackProfileCollectorPtr browser_interface);
 
+  // Returns the process-global metadata recorder instance used for tracking
+  // sampling profiler metadata.
+  static MetadataRecorder& GetStackSamplingProfilerMetadataRecorder();
+
  protected:
   // Test seam.
   virtual void PassProfilesToMetricsProvider(SampledProfile sampled_profile);