Delay GpuCommandBufferStub::AddDestructionObserver until we need it.

content/common/gpu/image_transport_surface.h

 // Copyright (c) 2012 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 CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 #define CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_
 
 #if defined(ENABLE_GPU)
 
 #include <vector>
@@ skipping 113 matching lines @@
 
   // Make the surface's context current.
   bool MakeCurrent();
 
   // Set the default swap interval on the surface.
   static void SetSwapInterval(gfx::GLContext* context);
 
   void Suspend();
 
   GpuChannelManager* manager() const { return manager_; }
+  GpuCommandBufferStub* stub() const { return stub_.get(); }
 
  private:
   gpu::GpuScheduler* Scheduler();
   gpu::gles2::GLES2Decoder* Decoder();
 
   // IPC::Message handlers.
   void OnBufferPresented(uint32 sync_point);
   void OnResizeViewACK();
   void OnSetFrontSurfaceIsProtected(bool is_protected,
                                     uint32 protection_state_id);
@@ skipping 44 matching lines @@
   gfx::Size new_size_;
   bool transport_;
   bool did_set_swap_interval_;
 
   DISALLOW_COPY_AND_ASSIGN(PassThroughImageTransportSurface);
 };
 
 #endif  // defined(ENABLE_GPU)
 
 #endif  // CONTENT_COMMON_GPU_IMAGE_TRANSPORT_SURFACE_H_