Split WebGraphicsContext3DCommandBufferImpl::initialize() into two stages.

content/renderer/gpu/renderer_gl_context.h

 // Copyright (c) 2011 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.
 
 // This API is consistent with other OpenGL setup APIs like window's WGL
 // and pepper's PGL. This API is used to manage OpenGL RendererGLContexts in the
 // Chrome renderer process in a way that is consistent with other platforms.
 
 #ifndef CONTENT_RENDERER_GPU_RENDERER_GL_CONTEXT_H_
 #define CONTENT_RENDERER_GPU_RENDERER_GL_CONTEXT_H_
@@ skipping 183 matching lines @@
   base::WeakPtr<RendererGLContext> parent_;
   scoped_ptr<Callback0::Type> swap_buffers_callback_;
   scoped_ptr<Callback1<ContextLostReason>::Type> context_lost_callback_;
   uint32 parent_texture_id_;
   CommandBufferProxy* command_buffer_;
   gpu::gles2::GLES2CmdHelper* gles2_helper_;
   int32 transfer_buffer_id_;
   gpu::gles2::GLES2Implementation* gles2_implementation_;
   Error last_error_;
   int frame_number_;
+#ifndef NDEBUG
+  // Used to assert that this object is used on a single thread.
+  MessageLoop* message_loop_;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(RendererGLContext);
 };
 
 #endif  // CONTENT_RENDERER_GPU_RENDERER_GL_CONTEXT_H_