Estimate draw duration in SchedulerClient

cc/trees/thread_proxy.h

Index: cc/trees/thread_proxy.h
diff --git a/cc/trees/thread_proxy.h b/cc/trees/thread_proxy.h
index ebd228befa2ab83b0185a48c772e1ad167026208..43424c6a56692199749ae5ae7e4eed544ce0dd7d 100644
--- a/cc/trees/thread_proxy.h
+++ b/cc/trees/thread_proxy.h
@@ -11,6 +11,7 @@
 #include "cc/animation/animation_events.h"
 #include "cc/base/completion_event.h"
 #include "cc/resources/resource_update_controller.h"
+#include "cc/scheduler/rolling_time_delta_history.h"
 #include "cc/scheduler/scheduler.h"
 #include "cc/scheduler/vsync_time_source.h"
 #include "cc/trees/layer_tree_host_impl.h"
@@ -102,6 +103,7 @@ class ThreadProxy : public Proxy,
   virtual void ScheduledActionBeginOutputSurfaceCreation() OVERRIDE;
   virtual void ScheduledActionAcquireLayerTexturesForMainThread() OVERRIDE;
   virtual void DidAnticipatedDrawTimeChange(base::TimeTicks time) OVERRIDE;
+  virtual base::TimeDelta DrawDurationEstimate() OVERRIDE;
 
   // ResourceUpdateControllerClient implementation
   virtual void ReadyToFinalizeTextureUpdates() OVERRIDE;
@@ -261,6 +263,8 @@ class ThreadProxy : public Proxy,
   base::TimeTicks smoothness_takes_priority_expiration_time_;
   bool renew_tree_priority_on_impl_thread_pending_;
 
+  RollingTimeDeltaHistory draw_duration_history_;
+
   DISALLOW_COPY_AND_ASSIGN(ThreadProxy);
 };