[DRAFT] Create RenderFrameHostManager.

content/common/frame_messages.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.
 
 // IPC messages for interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/content_export.h"
 #include "ipc/ipc_message_macros.h"
 
@@ skipping 24 matching lines @@
                     int64 /* parent_frame_id */,
                     int64 /* frame_id */)
 
 // Sent when the renderer starts a provisional load for a frame.
 IPC_MESSAGE_ROUTED4(FrameHostMsg_DidStartProvisionalLoadForFrame,
                     int64 /* frame_id */,
                     int64 /* parent_frame_id */,
                     bool /* true if it is the main frame */,
                     GURL /* url */)
 
+// Indicates that the current renderer has swapped out, after a SwapOut
+// message.
+IPC_MESSAGE_ROUTED0(FrameHostMsg_SwapOut_ACK)
+
+// Instructs the renderer 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)