Fix swapbuffers callback crash

chrome/renderer/webgraphicscontext3d_command_buffer_impl.h

 // Copyright (c) 2010 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 CHROME_RENDERER_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_
 #define CHROME_RENDERER_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
@@ skipping 354 matching lines @@
   virtual void requestExtensionCHROMIUM(const char*);
 
   virtual unsigned createCompositorTexture(unsigned width, unsigned height);
   virtual void deleteCompositorTexture(unsigned parent_texture);
   virtual void copyTextureToCompositor(unsigned texture,
                                        unsigned parent_texture);
 
   ggl::Context* context() { return context_; }
 
  private:
+  // SwapBuffers callback;
+  void OnSwapBuffers();
+
   // The GGL context we use for OpenGL rendering.
   ggl::Context* context_;
   // If rendering directly to WebView, weak pointer to it.
   WebKit::WebView* web_view_;
 #if defined(OS_MACOSX)
   // "Fake" plugin window handle in browser process for the compositor's output.
   gfx::PluginWindowHandle plugin_handle_;
 #endif
 
   WebKit::WebGraphicsContext3D::Attributes attributes_;
   int cached_width_, cached_height_;
 
   // For tracking which FBO is bound.
   unsigned int bound_fbo_;
 
   // Errors raised by synthesizeGLError().
   std::vector<unsigned long> synthetic_errors_;
 
 #ifdef FLIP_FRAMEBUFFER_VERTICALLY
   scoped_ptr<uint8> scanline_;
   void FlipVertically(uint8* framebuffer,
                       unsigned int width,
                       unsigned int height);
 #endif
 };
 
 #endif  // defined(ENABLE_GPU)
 #endif  // CHROME_RENDERER_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_