cc: Don't attempt main thread synchronization if it is slow.

cc/scheduler/scheduler.h

Index: cc/scheduler/scheduler.h
diff --git a/cc/scheduler/scheduler.h b/cc/scheduler/scheduler.h
index 58ad8000cc6128691198d87a916bb85d733bc768..26d8ffa6da044ccca54c6208e37e04ad094252a2 100644
--- a/cc/scheduler/scheduler.h
+++ b/cc/scheduler/scheduler.h
@@ -95,7 +95,8 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   void DidSwapBuffers();
   void DidSwapBuffersComplete();
 
-  void SetImplLatencyTakesPriority(bool impl_latency_takes_priority);
+  void SetSmoothnessMode(bool smoothness_takes_priority,
+                         bool scroll_affects_scroll_handler);
 
   void NotifyReadyToCommit();
   void BeginMainFrameAborted(CommitEarlyOutReason reason);
@@ -122,7 +123,7 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
     return !begin_impl_frame_deadline_task_.IsCancelled();
   }
   bool ImplLatencyTakesPriority() const {
-    return state_machine_.impl_latency_takes_priority();
+    return state_machine_.ImplLatencyTakesPriority();
   }
 
   void NotifyBeginMainFrameStarted();
@@ -192,9 +193,13 @@ class CC_EXPORT Scheduler : public BeginFrameObserverBase {
   void DrawAndSwapForced();
   void ProcessScheduledActions();
   void UpdateCompositorTimingHistoryRecordingEnabled();
-  bool ShouldRecoverMainLatency(const BeginFrameArgs& args) const;
-  bool ShouldRecoverImplLatency(const BeginFrameArgs& args) const;
-  bool CanCommitAndActivateBeforeDeadline(const BeginFrameArgs& args) const;
+  bool ShouldRecoverMainLatency(const BeginFrameArgs& args,
+                                bool can_activate_before_deadline) const;
+  bool ShouldRecoverImplLatency(const BeginFrameArgs& args,
+                                bool can_activate_before_deadline) const;
+  bool CanCommitAndActivateBeforeDeadline(
+      const BeginFrameArgs& args,
+      base::TimeDelta bmf_to_activate_estimate) const;
   void AdvanceCommitStateIfPossible();
   bool IsBeginMainFrameSentOrStarted() const;
   void BeginRetroFrame();