Make RenderFrame(Host) own a RenderWidget(Host).

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 341651a0c1cd9b76e4a8f77252335f6739ca3989..bcdc7b828e8d81e9d322a46dc7dc503999cf8576 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -53,6 +53,7 @@ class RenderFrameHostDelegate;
 class RenderFrameProxyHost;
 class RenderProcessHost;
 class RenderViewHostImpl;
+class RenderWidgetHostDelegate;
 class RenderWidgetHostImpl;
 class TimeoutMonitor;
 struct ContextMenuParams;
@@ -167,8 +168,14 @@ class CONTENT_EXPORT RenderFrameHostImpl
   RenderViewHostImpl* render_view_host() { return render_view_host_; }
   RenderFrameHostDelegate* delegate() { return delegate_; }
   FrameTreeNode* frame_tree_node() { return frame_tree_node_; }
-  // TODO(nasko): The RenderWidgetHost will be owned by RenderFrameHost in
-  // the future, so update this accessor to return the right pointer.
+
+  // This is called to create RenderWidgetHosts for out-of-process iframes.
+  void CreateRenderWidgetHost(RenderWidgetHostDelegate* delegate,
+                              bool hidden);
+
+  // This returns the RenderFrameHost's owned RenderWidgetHost if it has one,
+  // or else it returns a pointer to the RenderViewHost (which inherits
+  // RenderWidgetHost).
   RenderWidgetHostImpl* GetRenderWidgetHost();
 
   // This function is called when this is a swapped out RenderFrameHost that
@@ -492,6 +499,13 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // Map from notification_id to a callback to cancel them.
   std::map<int, base::Closure> cancel_notification_callbacks_;
 
+  // RenderFrameHosts that need management of the rendering and input events
+  // for their frame subtrees require RenderWidgetHosts. This typically
+  // means frames that are rendered in different processes from their parent
+  // frames.
+  // TODO(kenrb): Later this will also be used on the top-level frame.
+  scoped_ptr<RenderWidgetHostImpl> render_widget_host_;
+
   int routing_id_;
 
   // The current state of this RenderFrameHost.