Update from https://crrev.com/315085

cc/scheduler/begin_frame_source.h

Index: cc/scheduler/begin_frame_source.h
diff --git a/cc/scheduler/begin_frame_source.h b/cc/scheduler/begin_frame_source.h
index 299db8e31d9b36176ffc98c17092ccc251110fd3..1612a286e26a1a9c969f1d1c758046011a8ae576 100644
--- a/cc/scheduler/begin_frame_source.h
+++ b/cc/scheduler/begin_frame_source.h
@@ -138,7 +138,7 @@ class CC_EXPORT BeginFrameSourceMixIn : public BeginFrameSource {
 
   // BeginFrameSource
   bool NeedsBeginFrames() const override;
-  void SetNeedsBeginFrames(bool needs_begin_frames) override;
+  void SetNeedsBeginFrames(bool needs_begin_frames) final;
   void DidFinishFrame(size_t remaining_frames) override {}
   void AddObserver(BeginFrameObserver* obs) final;
   void RemoveObserver(BeginFrameObserver* obs) final;
@@ -261,9 +261,11 @@ class CC_EXPORT BeginFrameSourceMultiplexer : public BeginFrameSourceMixIn,
 
   // BeginFrameSource
   bool NeedsBeginFrames() const override;
-  void SetNeedsBeginFrames(bool needs_begin_frames) override;
   void DidFinishFrame(size_t remaining_frames) override;
 
+  // BeginFrameSourceMixIn
+  void OnNeedsBeginFramesChange(bool needs_begin_frames) override;
+
   // Tracing
   void AsValueInto(base::debug::TracedValue* dict) const override;