Don't call renderView methods in threaded mode

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.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.
 
 #ifndef CONTENT_RENDERER_GPU_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_
 #define CONTENT_RENDERER_GPU_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_
 #pragma once
 
 #if defined(ENABLE_GPU)
 
@@ skipping 476 matching lines @@
   RendererGLContext* context_;
   // The GLES2Implementation we use for OpenGL rendering.
   gpu::gles2::GLES2Implementation* gl_;
 
   // State needed by MaybeInitializeGL.
   GpuChannelHost* host_;
   GURL active_url_;
   int32 render_view_routing_id_;
 
   bool render_directly_to_web_view_;
+
   // If rendering directly to WebView, weak pointer to it.
+  // This is only set when the context is bound to the main thread.
   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
   WebGraphicsContext3D::WebGraphicsContextLostCallback* context_lost_callback_;
   WGC3Denum context_lost_reason_;
 
   WebGraphicsContext3D::WebGraphicsSwapBuffersCompleteCallbackCHROMIUM*
@@ skipping 14 matching lines @@
 #ifdef FLIP_FRAMEBUFFER_VERTICALLY
   scoped_array<uint8> scanline_;
   void FlipVertically(uint8* framebuffer,
                       unsigned int width,
                       unsigned int height);
 #endif
 };
 
 #endif  // defined(ENABLE_GPU)
 #endif  // CONTENT_RENDERER_GPU_WEBGRAPHICSCONTEXT3D_COMMAND_BUFFER_IMPL_H_