SetPreviousFrameSurface should copy latency info to the new surface

cc/surfaces/surface.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SURFACES_SURFACE_H_
 #define CC_SURFACES_SURFACE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 114 matching lines @@
   void ActivatePendingFrame();
   // Called when all of the surface's dependencies have been resolved.
   void ActivateFrame(CompositorFrame frame);
   void UpdateBlockingSurfaces(
       const base::Optional<CompositorFrame>& previous_pending_frame,
       const CompositorFrame& current_frame);
 
   void UnrefFrameResources(const CompositorFrame& frame_data);
   void ClearCopyRequests();
 
+  void TakeLatencyInfoFromPendingFrame(
+      std::vector<ui::LatencyInfo>* latency_info);
+  void TakeLatencyInfoFromFrame(CompositorFrame* frame,

[jbauman, 2017/03/01 22:11:08]

Make this static.

[Saman Sami, 2017/03/01 22:35:05]

Done.

+                                std::vector<ui::LatencyInfo>* latency_info);
+
   SurfaceId surface_id_;
   SurfaceId previous_frame_surface_id_;
   base::WeakPtr<SurfaceFactory> factory_;
   // TODO(jamesr): Support multiple frames in flight.
   base::Optional<CompositorFrame> pending_frame_;
   base::Optional<CompositorFrame> active_frame_;
   int frame_index_;
   bool destroyed_;
   std::vector<SurfaceSequence> destruction_dependencies_;
 
   // This surface may have multiple BeginFrameSources if it is
   // on multiple Displays.
   std::set<BeginFrameSource*> begin_frame_sources_;
 
   SurfaceDependencies blocking_surfaces_;
   base::ObserverList<PendingFrameObserver, true> observers_;
 
   DrawCallback draw_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 using PendingSurfaceSet = base::flat_set<Surface*>;
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_H_