Resetting FrameTreeNode must remove child FrameTreeNodes from global map.

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 58 matching lines @@
   // it safe to remove children during the callback.
   void ForEach(const base::Callback<bool(FrameTreeNode*)>& on_node) const;
 
   // Frame tree manipulation routines.
   RenderFrameHostImpl* AddFrame(FrameTreeNode* parent,
                                 int process_id,
                                 int new_routing_id,
                                 const std::string& frame_name);
   void RemoveFrame(FrameTreeNode* child);
 
+  // This method only removes the FrameTreeNode from the global map of ids

[Charlie Reis, 2015/02/12 17:12:43]

It feels a bit odd to have a public method for modifying a private global map. 
It would be nice to hide this behind RemoveFrame.

[nasko, 2015/02/12 23:21:08]

Done.

+  // to objects.
+  void RemoveNodeFromMap(int64 frame_tree_node_id);
+
   // This method walks the entire frame tree and creates a RenderFrameProxyHost
   // for the given |site_instance| in each node except the |source| one --
   // the source will have a RenderFrameHost. It assumes that no frame tree
   // nodes already have RenderFrameProxyHost for the given |site_instance|.
   void CreateProxiesForSiteInstance(
       FrameTreeNode* source,
       SiteInstance* site_instance);
 
   // Clears process specific-state after a main frame process swap.
   // This destroys most of the frame tree but retains the root node so that
@@ skipping 74 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_