Surface Synchronization: Distinguish between dependencies and references

cc/surfaces/referenced_surface_tracker.h

 // Copyright 2016 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_REFERENCED_SURFACE_TRACKER_H_
 #define CC_SURFACES_REFERENCED_SURFACE_TRACKER_H_
 
 #include <unordered_set>
 #include <vector>
 
@@ skipping 23 matching lines @@
     return references_to_remove_;
   }
 
   // Update the references for a CompositorFrame. If |local_surface_id| has
   // changed then new references will be generated for everything in
   // |referenced_surfaces|. Otherwise a diff from the referenced surfaces in the
   // last frame will be computed. This should be called once per
   // CompositorFrame.
   void UpdateReferences(
       const LocalSurfaceId& local_surface_id,
-      const std::vector<SurfaceId>* active_referenced_surfaces,
-      const std::vector<SurfaceId>* pending_referenced_surfaces);
+      const std::vector<SurfaceId>* active_referenced_surfaces);
 
  private:
   // Updates |referenced_surfaces_| based on a |new_referenced_surfaces| from a
   // CompositorFrame. Populates |references_to_add_| and |references_to_remove_|
   // based on the difference between the sets.
   void ProcessNewReferences(const std::unordered_set<SurfaceId, SurfaceIdHash>&
                                 new_referenced_surfaces);
 
   // Adds reference from |current_surface_id_| to |surface_id|.
   void AddSurfaceReference(const SurfaceId& surface_id);
@@ skipping 15 matching lines @@
   // CompositorFrame has been submitted and the surfaces are no longer needed by
   // |current_surface_id_|.
   std::vector<SurfaceReference> references_to_remove_;
 
   DISALLOW_COPY_AND_ASSIGN(ReferencedSurfaceTracker);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_REFERENCED_SURFACE_TRACKER_H_