Report the duration of sampled tasks with histogram.

components/scheduler/renderer/renderer_scheduler_impl.h

Index: components/scheduler/renderer/renderer_scheduler_impl.h
diff --git a/components/scheduler/renderer/renderer_scheduler_impl.h b/components/scheduler/renderer/renderer_scheduler_impl.h
index d662dd45247bfbc44717b04897dc22e3ae2eed74..7795dd7538a285c57dea90721810b10ed9c04e7f 100644
--- a/components/scheduler/renderer/renderer_scheduler_impl.h
+++ b/components/scheduler/renderer/renderer_scheduler_impl.h
@@ -18,6 +18,7 @@
 #include "components/scheduler/renderer/idle_time_estimator.h"
 #include "components/scheduler/renderer/render_widget_signals.h"
 #include "components/scheduler/renderer/renderer_scheduler.h"
+#include "components/scheduler/renderer/renderer_task_duration.h"
 #include "components/scheduler/renderer/task_cost_estimator.h"
 #include "components/scheduler/renderer/throttling_helper.h"
 #include "components/scheduler/renderer/user_model.h"
@@ -135,6 +136,10 @@ class SCHEDULER_EXPORT RendererSchedulerImpl
   void ReportTaskTime(base::TimeTicks start_time,
                       base::TimeTicks end_time) override;
 
+  // Sample Tasks and Report in histogrtam":
+  void ReportSampleDuration(base::TimeTicks start_time,
+                            base::TimeTicks end_time);
+

[majidvp, 2016/07/27 13:50:59]

I think this is is not longer needed.

[sunyunjia, 2016/07/27 17:28:42]

Done.

   // QueueingTimeEstimator::Client implementation:
   void OnQueueingTimeForWindowEstimated(base::TimeDelta queueing_time) override;
 
@@ -470,6 +475,9 @@ class SCHEDULER_EXPORT RendererSchedulerImpl
   }
 
   PollableThreadSafeFlag policy_may_need_update_;
+
+  RendererTaskDuration renderer_task_duration_;
+
   base::WeakPtrFactory<RendererSchedulerImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererSchedulerImpl);