Create RenderFrameProxyHost at time of swap-out instead of commit.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index 6dbe9302c03da24f1c5ea42737103c232c034252..dadb8898de4dc6d7cc302546f41c3df86374fd7d 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -301,9 +301,10 @@ IPC_MESSAGE_ROUTED1(FrameMsg_Navigate, FrameMsg_Navigate_Params)
 IPC_MESSAGE_ROUTED0(FrameMsg_BeforeUnload)
 
 // Instructs the frame to swap out for a cross-site transition, including
-// running the unload event handler. Expects a SwapOut_ACK message when
-// finished.
-IPC_MESSAGE_ROUTED0(FrameMsg_SwapOut)
+// running the unload event handler and creating a RenderFrameProxy with the
+// given |proxy_routing_id|. Expects a SwapOut_ACK message when finished.
+IPC_MESSAGE_ROUTED1(FrameMsg_SwapOut,
+                    int /* proxy_routing_id */)
 
 // Request for the renderer to insert CSS into the frame.
 IPC_MESSAGE_ROUTED1(FrameMsg_CSSInsertRequest,
@@ -353,6 +354,10 @@ IPC_MESSAGE_ROUTED2(FrameMsg_DidChooseColorResponse, unsigned, SkColor)
 // Notifies the color chooser client that the color chooser has ended.
 IPC_MESSAGE_ROUTED1(FrameMsg_DidEndColorChooser, unsigned)
 
+// Notifies the corresponding RenderFrameProxy object to replace itself with the
+// RenderFrame object it is associated with.
+IPC_MESSAGE_ROUTED0(FrameMsg_DeleteProxy)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.