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

content/browser/renderer_host/render_message_filter.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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
@@ skipping 175 matching lines @@
       int plugin_child_id,
       int32 pp_instance,
       PepperRendererInstanceData instance_data,
       bool is_external);
   void OnDidDeleteOutOfProcessPepperInstance(int plugin_child_id,
                                              int32 pp_instance,
                                              bool is_external);
   void OnOpenChannelToPpapiBroker(int routing_id,
                                   const base::FilePath& path);
   void OnGenerateRoutingID(int* route_id);
-  void OnDownloadUrl(const IPC::Message& message,
+  void OnDownloadUrl(int render_view_id,
                      const GURL& url,
                      const Referrer& referrer,
                      const base::string16& suggested_name,
                      const bool use_prompt);
   void OnCheckNotificationPermission(const GURL& source_origin,
                                      int* permission_level);
 
   void OnGetCPUUsage(int* cpu_usage);
 
   void OnGetAudioHardwareConfig(media::AudioParameters* input_params,
@@ skipping 116 matching lines @@
 #if defined(OS_MACOSX)
   base::ScopedCFTypeRef<CFTypeRef> last_io_surface_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(RenderMessageFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_MESSAGE_FILTER_H_