Enable startup profiling by Win x64 stack sampling profiler

components/metrics/call_stack_profile_metrics_provider.h

Index: components/metrics/call_stack_profile_metrics_provider.h
diff --git a/components/metrics/call_stack_profile_metrics_provider.h b/components/metrics/call_stack_profile_metrics_provider.h
index 6d5ff8ccab362ead89d94c8ec8f62db03f8ff643..33f7f775622d049b1d23723885180509aa015c32 100644
--- a/components/metrics/call_stack_profile_metrics_provider.h
+++ b/components/metrics/call_stack_profile_metrics_provider.h
@@ -7,9 +7,15 @@
 
 #include <vector>
 
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/profiler/stack_sampling_profiler.h"
 #include "components/metrics/metrics_provider.h"
 
+namespace base {
+class MessageLoopProxy;
+}  // namespace base
+
 namespace metrics {
 class ChromeUserMetricsExtension;
 
@@ -20,18 +26,38 @@ class CallStackProfileMetricsProvider : public MetricsProvider {
   ~CallStackProfileMetricsProvider() override;
 
   // MetricsProvider:
+  void OnRecordingEnabled() override;
+  void OnRecordingDisabled() override;
   void ProvideGeneralMetrics(ChromeUserMetricsExtension* uma_proto) override;
 
-  // Uses |profiles| as the source data for the next invocation of
-  // ProvideGeneralMetrics, rather than sourcing them from the
-  // StackSamplingProfiler.
-  void SetSourceProfilesForTesting(
+  // Appends |profiles| for use by the next invocation of ProvideGeneralMetrics,
+  // rather than sourcing them from the StackSamplingProfiler.
+  void AppendSourceProfilesForTesting(
       const std::vector<base::StackSamplingProfiler::CallStackProfile>&
           profiles);
 
+ protected:
+  // Finch field trial and group for reporting profiles. Provided here for test
+  // use.
+  static const char kFieldTrialName[];
+  static const char kReportProfilesGroupName[];
+
  private:
-  std::vector<base::StackSamplingProfiler::CallStackProfile>
-      source_profiles_for_test_;
+  // Returns true if reporting of profiles is enabled according to the
+  // controlling Finch field trial.
+  static bool IsSamplingProfilingReportingEnabled();
+
+  // Invoked by the profiler on another thread.
+  static void ReceiveCompletedProfiles(
+      scoped_refptr<base::MessageLoopProxy> message_loop,
+      base::WeakPtr<CallStackProfileMetricsProvider> provider,
+      const base::StackSamplingProfiler::CallStackProfiles& profiles);
+  void AppendCompletedProfiles(
+      const base::StackSamplingProfiler::CallStackProfiles& profiles);
+
+  base::StackSamplingProfiler::CallStackProfiles pending_profiles_;
+
+  base::WeakPtrFactory<CallStackProfileMetricsProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CallStackProfileMetricsProvider);
 };