Navigation transitions: Block first response until after transitions have run.

content/browser/renderer_host/render_message_filter.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_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 262 matching lines @@
                             uint32_t data_size);
 #endif
 
   void OnAllocateGpuMemoryBuffer(uint32 width,
                                  uint32 height,
                                  uint32 internalformat,
                                  uint32 usage,
                                  IPC::Message* reply);
   void GpuMemoryBufferAllocated(IPC::Message* reply,
                                 const gfx::GpuMemoryBufferHandle& handle);
+  void OnSetHasPendingTransitionRequest(int frame_id, bool is_transition);

[jam, 2014/06/18 00:34:25]

nit: rendre_frame_id here as well, and in the cc file

 
   // Cached resource request dispatcher host and plugin service, guaranteed to
   // be non-null if Init succeeds. We do not own the objects, they are managed
   // by the BrowserProcess, which has a wider scope than we do.
   ResourceDispatcherHostImpl* resource_dispatcher_host_;
   PluginServiceImpl* plugin_service_;
   base::FilePath profile_data_directory_;
 
   // Contextual information to be used for requests created here.
   scoped_refptr<net::URLRequestContextGetter> request_context_;
@@ skipping 31 matching lines @@
 #if defined(OS_MACOSX)
   base::ScopedCFTypeRef<CFTypeRef> last_io_surface_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RenderMessageFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_