Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/renderer_host/render_frame_host_impl.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_RENDERER_HOST_RENDER_FRAME_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_FRAME_HOST_IMPL_H_
 
+#include <string>
+
 #include "base/compiler_specific.h"
 #include "content/public/browser/render_frame_host.h"
 
 namespace content {
 
+class FrameTree;
 class RenderProcessHost;
-class RenderViewHostImpl;
 
 class CONTENT_EXPORT RenderFrameHostImpl : public RenderFrameHost {
  public:
   static RenderFrameHostImpl* FromID(int process_id, int routing_id);
 
-  RenderFrameHostImpl(RenderViewHostImpl* render_view_host,
+  RenderFrameHostImpl(RenderProcessHost* render_process_host,
+                      FrameTree* frame_tree,
                       int routing_id,
                       bool is_swapped_out);
   virtual ~RenderFrameHostImpl();
 
   // IPC::Sender
   virtual bool Send(IPC::Message* msg) OVERRIDE;
 
   // IPC::Listener
   virtual bool OnMessageReceived(const IPC::Message& msg) OVERRIDE;
 
   void Init();
   RenderProcessHost* GetProcess() const;
   int routing_id() const { return routing_id_; }
+  void OnCreateChildFrame(int new_frame_routing_id,
+                          int64 parent_frame_id,
+                          int64 frame_id,
+                          const std::string& frame_name);
 
  private:
   bool is_swapped_out() { return is_swapped_out_; }
 
-  RenderViewHostImpl* render_view_host_;  // Not owned. Outlives this object.
+  // IPC message handlers.
+  void OnDetach(int64 parent_frame_id, int64 frame_id);
+
+  RenderProcessHost* render_process_host_;  // Not owned.
+
+  FrameTree* frame_tree_;

[Charlie Reis, 2013/09/27 19:19:21]

Either here or on the constructor, we should explain this so that people don't
misinterpret it as the FrameTreeNode for this RFH (since it has the same name as
the tree node class in Blink).

Basically, this is giving each RFH a pointer to the whole tree (not its own
node) so that it can add/remove nodes to the tree.

[awong, 2013/09/27 20:50:09]

Done.

   int routing_id_;
   bool is_swapped_out_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_FRAME_HOST_IMPL_H_