Add way to mark other Surface a predecessor for a 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 26 matching lines @@
 class SurfaceResourceHolder;
 
 class CC_SURFACES_EXPORT Surface {
  public:
   using DrawCallback = SurfaceFactory::DrawCallback;
 
   Surface(SurfaceId id, SurfaceFactory* factory);
   ~Surface();
 
   SurfaceId surface_id() const { return surface_id_; }
+  SurfaceId previous_frame_surface_id() const {
+    return previous_frame_surface_id_;
+  }
+
+  void SetPreviousFrameSurface(Surface* surface);
 
   void QueueFrame(std::unique_ptr<CompositorFrame> frame,
                   const DrawCallback& draw_callback);
   void RequestCopyOfOutput(std::unique_ptr<CopyOutputRequest> copy_request);
   // Adds each CopyOutputRequest in the current frame to copy_requests. The
   // caller takes ownership of them.
   void TakeCopyOutputRequests(
       std::multimap<RenderPassId, std::unique_ptr<CopyOutputRequest>>*
           copy_requests);
   // Returns the most recent frame that is eligible to be rendered.
@@ skipping 24 matching lines @@
     return referenced_surfaces_;
   }
 
   bool destroyed() const { return destroyed_; }
   void set_destroyed(bool destroyed) { destroyed_ = destroyed; }
 
  private:
   void ClearCopyRequests();
 
   SurfaceId surface_id_;
+  SurfaceId previous_frame_surface_id_;
   base::WeakPtr<SurfaceFactory> factory_;
   // TODO(jamesr): Support multiple frames in flight.
   std::unique_ptr<CompositorFrame> current_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_;
 
   std::vector<SurfaceId> referenced_surfaces_;
 
   DrawCallback draw_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_H_