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

content/browser/renderer_host/render_view_host_delegate.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_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 28 matching lines @@
 
 namespace gfx {
 class Point;
 class Rect;
 class Size;
 }
 
 namespace content {
 
 class BrowserContext;
+class FrameTree;
 class PageState;
 class RenderViewHost;
 class RenderViewHostDelegateView;
 class SessionStorageNamespace;
 class SiteInstance;
 class WebContents;
 class WebContentsImpl;
 struct ContextMenuParams;
 struct FileChooserParams;
 struct GlobalRequestID;
@@ skipping 370 matching lines @@
   // calling |callback|.
   virtual void RequestMediaAccessPermission(
       const MediaStreamRequest& request,
       const MediaResponseCallback& callback) {}
 
   // Returns the SessionStorageNamespace the render view should use. Might
   // create the SessionStorageNamespace on the fly.
   virtual SessionStorageNamespace* GetSessionStorageNamespace(
       SiteInstance* instance);
 
+  // Returns the FrameTree the render view should use. Guaranteed to be constant
+  // for the lifetime of the render view.
+  //
+  // TODO(ajwong): Remove once the main frame RenderFrameHost is no longer
+  // created by the RenderViewHost.
+  virtual FrameTree* GetFrameTree();
+
  protected:
   virtual ~RenderViewHostDelegate() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_DELEGATE_H_