Add support for passing an arbitrary parameter to an IPC message handler. The motivation is for Web…

content/renderer/browser_plugin/browser_plugin_manager_impl.cc

 // 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.
 
 #include "content/renderer/browser_plugin/browser_plugin_manager_impl.h"
 
 #include "content/common/browser_plugin/browser_plugin_constants.h"
 #include "content/common/browser_plugin/browser_plugin_messages.h"
 #include "content/common/cursors/webcursor.h"
 #include "content/renderer/browser_plugin/browser_plugin.h"
@@ skipping 56 matching lines @@
 
 void BrowserPluginManagerImpl::DidCommitCompositorFrame() {
   IDMap<BrowserPlugin>::iterator iter(&instances_);
   while (!iter.IsAtEnd()) {
     iter.GetCurrentValue()->DidCommitCompositorFrame();
     iter.Advance();
   }
 }
 
 void BrowserPluginManagerImpl::OnAllocateInstanceIDACK(
-    const IPC::Message& message,
     int request_id,
     int guest_instance_id) {
   InstanceIDMap::iterator it =
       pending_allocate_guest_instance_id_requests_.find(request_id);
   if (it == pending_allocate_guest_instance_id_requests_.end())
     return;
 
   const base::WeakPtr<BrowserPlugin> plugin(it->second);
   if (!plugin)
     return;
   pending_allocate_guest_instance_id_requests_.erase(request_id);
   plugin->OnInstanceIDAllocated(guest_instance_id);
 }
 
 }  // namespace content