Keep a copy of page id in RenderViewHost.

content/renderer/render_view_impl.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_RENDERER_RENDER_VIEW_IMPL_H_
 #define CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 899 matching lines @@
   // TODO(nasko): Move to RenderFrame, as this is per-frame state.
   scoped_ptr<FrameMsg_Navigate_Params> pending_navigation_params_;
 
   // Timer used to delay the updating of nav state (see SyncNavigationState).
   base::OneShotTimer<RenderViewImpl> nav_state_sync_timer_;
 
   // Page IDs ------------------------------------------------------------------
   // See documentation in RenderView.
   int32 page_id_;
 
+  // TEMPORARY <http://crbug.com/407376>. If true, then |page_id_| has been
+  // changed but not yet reported to the browser process. No IPCs should be sent
+  // with a page_id_ while this is true.
+  bool page_id_not_yet_reported_;
+
   // Indicates the ID of the last page that we sent a FrameNavigate to the
   // browser for. This is used to determine if the most recent transition
   // generated a history entry (less than page_id_), or not (equal to or
   // greater than). Note that this will be greater than page_id_ if the user
   // goes back.
   int32 last_page_id_sent_to_browser_;
 
   // The next available page ID to use for this RenderView.  These IDs are
   // specific to a given RenderView and the frames within it.
   int32 next_page_id_;
@@ skipping 198 matching lines @@
   // use the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_IMPL_H_