Do not create proxy hosts in the subtree of navigating frame.

content/browser/frame_host/frame_tree.h

 // Copyright 2013 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_FRAME_HOST_FRAME_TREE_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 117 matching lines @@
 
   // Keeps track of which RenderFrameHosts are using each RenderViewHost.  When
   // the number drops to zero, we call Shutdown on the RenderViewHost.
   void RegisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
   void UnregisterRenderFrameHost(RenderFrameHostImpl* render_frame_host);
 
  private:
   typedef base::hash_map<int, RenderViewHostImpl*> RenderViewHostMap;
   typedef std::multimap<int, RenderViewHostImpl*> RenderViewHostMultiMap;
 
+  // A variation to the public ForEach method with a difference that the subtree
+  // starting at |skip_node| will not be recursed into.
+  void ForEach(const base::Callback<bool(FrameTreeNode*)>& on_node,
+               FrameTreeNode* skip_this_subtree) const;
+
   // These delegates are installed into all the RenderViewHosts and
   // RenderFrameHosts that we create.
   RenderFrameHostDelegate* render_frame_delegate_;
   RenderViewHostDelegate* render_view_delegate_;
   RenderWidgetHostDelegate* render_widget_delegate_;
   RenderFrameHostManager::Delegate* manager_delegate_;
 
   // Map of SiteInstance ID to a RenderViewHost.  This allows us to look up the
   // RenderViewHost for a given SiteInstance when creating RenderFrameHosts.
   // Combined with the refcount on RenderViewHost, this allows us to call
@@ skipping 16 matching lines @@
   int64 focused_frame_tree_node_id_;
 
   base::Callback<void(RenderFrameHost*)> on_frame_removed_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameTree);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_TREE_H_