Enable swapping a frame back in to its parent process

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 1d9be84746a0118baef26b39d2f79dd6ea2d271e..10a322e9adf8a668efaa121ce81c6067c748624a 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -360,9 +360,12 @@ IPC_MESSAGE_ROUTED0(FrameMsg_DisownOpener)
 // Instructs the renderer to create a new RenderFrame object with |routing_id|.
 // The new frame should be created as a child of the object identified by
 // |parent_routing_id| or as top level if that is MSG_ROUTING_NONE.
-IPC_MESSAGE_CONTROL2(FrameMsg_NewFrame,
+// If a valid |proxy_routing_id| is provided, the new frame will be configured
+// to replace the proxy on commit.
+IPC_MESSAGE_CONTROL3(FrameMsg_NewFrame,
                      int /* routing_id */,
-                     int /* parent_routing_id */)
+                     int /* parent_routing_id */,
+                     int /* proxy_routing_id */)
 
 // Instructs the renderer to create a new RenderFrameProxy object with
 // |routing_id|. The new proxy should be created as a child of the object