Avoid destroying surface before the parent surface stops referencing it.

mojo/services/view_manager/context_factory_impl.h

 // Copyright 2013 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 MOJO_SERVICES_VIEW_MANAGER_CONTEXT_FACTORY_IMPL_H_
 #define MOJO_SERVICES_VIEW_MANAGER_CONTEXT_FACTORY_IMPL_H_
 
 #include "mojo/public/cpp/system/core.h"
 #include "ui/compositor/compositor.h"
 
@@ skipping 20 matching lines @@
       ui::Compositor* compositor,
       ui::Layer* layer) OVERRIDE;
   virtual void RemoveReflector(scoped_refptr<ui::Reflector> reflector) OVERRIDE;
 
   virtual scoped_refptr<cc::ContextProvider>
       SharedMainThreadContextProvider() OVERRIDE;
   virtual void RemoveCompositor(ui::Compositor* compositor) OVERRIDE;
   virtual bool DoesCreateTestContexts() OVERRIDE;
   virtual cc::SharedBitmapManager* GetSharedBitmapManager() OVERRIDE;
   virtual base::MessageLoopProxy* GetCompositorMessageLoop() OVERRIDE;
+  virtual scoped_ptr<cc::SurfaceIdAllocator> CreateSurfaceIdAllocator()
+      OVERRIDE;
 
  private:
   scoped_refptr<webkit::gpu::ContextProviderInProcess>
       shared_main_thread_contexts_;
 
   ScopedMessagePipeHandle command_buffer_handle_;
+  uint32_t next_surface_id_namespace_;
 
   // TODO(sky): for debugging, remove.
   bool did_create_;
 
   DISALLOW_COPY_AND_ASSIGN(ContextFactoryImpl);
 };
 
 }  // namespace service
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_VIEW_MANAGER_CONTEXT_FACTORY_IMPL_H_