Remove page id from ViewHostMsg_UpdateTargetURL; no one actually uses it on the browser side.

content/common/view_messages.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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 1057 matching lines @@
 IPC_MESSAGE_ROUTED0(ViewHostMsg_ClosePage_ACK)
 
 // Notifies the browser that we have session history information.
 // page_id: unique ID that allows us to distinguish between history entries.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_UpdateState,
                     int32 /* page_id */,
                     content::PageState /* state */)
 
 // Notifies the browser that we want to show a destination url for a potential
 // action (e.g. when the user is hovering over a link).
-IPC_MESSAGE_ROUTED2(ViewHostMsg_UpdateTargetURL,
-                    int32,
+IPC_MESSAGE_ROUTED1(ViewHostMsg_UpdateTargetURL,
                     GURL)
 
 // Sent when the document element is available for the top-level frame.  This
 // happens after the page starts loading, but before all resources are
 // finished.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DocumentAvailableInMainFrame,
                     bool /* uses_temporary_zoom_level */)
 
 // Sent when the renderer loads a resource from its memory cache.
 // The security info is non empty if the resource was originally loaded over
@@ skipping 543 matching lines @@
 // Since the browser keeps handles to the allocated transport DIBs, this
 // message is sent to tell the browser that it may release them when the
 // renderer is finished with them.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_FreeTransportDIB,
                      TransportDIB::Id /* DIB id */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.