Create RenderFrameProxyHost at time of swap-out instead of commit.

content/common/view_messages.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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 428 matching lines @@
 
   // Preferences for this view.
   IPC_STRUCT_MEMBER(WebPreferences, web_preferences)
 
   // The ID of the view to be created.
   IPC_STRUCT_MEMBER(int32, view_id)
 
   // The ID of the main frame hosted in the view.
   IPC_STRUCT_MEMBER(int32, main_frame_routing_id)
 
+  // The ID of the proxy object for the main frame in this view. It is only
+  // used if |swapped_out| is true.

[Charlie Reis, 2014/05/15 00:32:50]

Maybe it should be declared just below swapped_out?

[nasko, 2014/05/15 18:47:13]

It made sense to group it with all routing ids. If you feel strongly, I'll move
it.

+  IPC_STRUCT_MEMBER(int32, proxy_routing_id)
+
   // The ID of the rendering surface.
   IPC_STRUCT_MEMBER(int32, surface_id)
 
   // The session storage namespace ID this view should use.
   IPC_STRUCT_MEMBER(int64, session_storage_namespace_id)
 
   // The name of the frame associated with this view (or empty if none).
   IPC_STRUCT_MEMBER(base::string16, frame_name)
 
   // The route ID of the opener RenderView if we need to set one
@@ skipping 1305 matching lines @@
 // synchronously (see crbug.com/120597). This IPC message sends the character
 // bounds after every composition change to always have correct bound info.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_ImeCompositionRangeChanged,
                     gfx::Range /* composition range */,
                     std::vector<gfx::Rect> /* character bounds */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.