Avoid destroying surface before the parent surface stops referencing it.

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>

[jamesr, 2014/09/12 01:08:55]

#include <vector> since you use it on line 48 and aren't allowed to fwd declare
std::vector

[jbauman, 2014/09/23 01:58:05]

Done.

+
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "cc/surfaces/surface_damage_observer.h"
 #include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_sequence.h"
 #include "cc/surfaces/surfaces_export.h"
 
 namespace cc {
 class CompositorFrame;
 class Surface;
 
 class CC_SURFACES_EXPORT SurfaceManager {
  public:
   SurfaceManager();
   ~SurfaceManager();
 
   void RegisterSurface(Surface* surface);
   void DeregisterSurface(SurfaceId surface_id);
 
+  // Destroy the Surface once a set of sequence numbers has been received.

[jamesr, 2014/09/12 01:08:55]

terminology nit: s/received/satisfied/

[jbauman, 2014/09/23 01:58:05]

Done.

+  void DestroyOnSequence(scoped_ptr<Surface> surface,
+                         const std::set<SurfaceSequence>& dependency_set);
+
   Surface* GetSurfaceForId(SurfaceId surface_id);
 
   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.
+  void SatisfiesSequence(SurfaceId id, std::vector<uint32_t>* sequence);
+
  private:
+  void AttemptSatisfyDestroy();

[jamesr, 2014/09/12 01:08:55]

i feel like this name could be a bit better.  This is really sweeping all
dependencies to see if any can be satisfied, maybe call it
SearchForSatisfaction()?

[jbauman, 2014/09/23 01:58:05]

Done.

+
   typedef base::hash_map<SurfaceId, Surface*> SurfaceMap;
   SurfaceMap surface_map_;
   ObserverList<SurfaceDamageObserver> observer_list_;
 
+  // List of surfaces to be destroyed, along with what sequences they're still
+  // waiting on.
+  typedef std::list<std::pair<Surface*, std::set<SurfaceSequence> > >

[jamesr, 2014/09/12 01:08:55]

we can do >>> now

+      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_