Allow layers to signal that additional sequences are needed before surface destruction

cc/surfaces/surface_manager.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_MANAGER_H_
 #define CC_SURFACES_SURFACE_MANAGER_H_
 
 #include <list>
 #include <set>
 #include <vector>
@@ skipping 28 matching lines @@
   void AddObserver(SurfaceDamageObserver* obs) {
     observer_list_.AddObserver(obs);
   }
 
   void RemoveObserver(SurfaceDamageObserver* obs) {
     observer_list_.RemoveObserver(obs);
   }
 
   void SurfaceModified(SurfaceId surface_id);
 
   // A frame for a surface satisfies a set of sequence numbers.

[jamesr, 2014/10/29 00:51:10]

can you update the comment to clarify that the set of sequence numbers all come
from the specified id namespace? the decomposition of sequences into the two
pairs isn't completely obvious otherwise, imo

-  void DidSatisfySequences(SurfaceId id, std::vector<uint32_t>* sequence);
+  void DidSatisfySequences(uint32_t id_namespace,
+                           std::vector<uint32_t>* sequence);
 
  private:
   void SearchForSatisfaction();
 
   typedef base::hash_map<SurfaceId, Surface*> SurfaceMap;
   SurfaceMap surface_map_;
   ObserverList<SurfaceDamageObserver> observer_list_;
   base::ThreadChecker thread_checker_;
 
   // List of surfaces to be destroyed, along with what sequences they're still
   // waiting on.
   typedef std::list<std::pair<Surface*, std::set<SurfaceSequence>>>
       SurfaceDestroyList;
   SurfaceDestroyList surfaces_to_destroy_;
 
   // Set of SurfaceSequences that have been satisfied by a frame but not yet
   // waited on.
   std::set<SurfaceSequence> satisfied_sequences_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_MANAGER_H_