Plumb activation time to main

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 9efd831d76aad31df9c7b6e41d5484cd8eb7265b..9f219c1b6695b3e915c5b580e067e2ec45d964ff 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -48,6 +48,7 @@ class SchedulerClient {
   virtual void ScheduledActionPerformImplSideInvalidation() = 0;
   virtual void DidFinishImplFrame() = 0;
   virtual void SendBeginMainFrameNotExpectedSoon() = 0;
+  virtual int SyncTreeSourceFrameNumber() = 0;
 
  protected:
   virtual ~SchedulerClient() {}
@@ -185,6 +186,9 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
 
   bool stopped_;
 
+  base::TimeTicks ready_to_activate_time_;
+  int ready_to_activate_source_frame_number_;
+
  private:
   void ScheduleBeginImplFrameDeadline();
   void ScheduleBeginImplFrameDeadlineIfNeeded();