Make BrowserMessageFilter not derive from IPC::ChannelProxy::MessageFilter. This allows us to hide …

content/browser/renderer_host/pepper/browser_ppapi_host_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/browser/renderer_host/pepper/browser_ppapi_host_impl.h"
 
 #include "content/browser/renderer_host/pepper/pepper_message_filter.h"
 #include "content/browser/tracing/trace_message_filter.h"
 #include "content/common/pepper_renderer_instance_data.h"
 #include "content/public/browser/render_view_host.h"
@@ skipping 12 matching lines @@
     int render_view_id,
     const base::FilePath& profile_directory) {
   // The plugin name and path shouldn't be needed for external plugins.
   BrowserPpapiHostImpl* browser_ppapi_host =
       new BrowserPpapiHostImpl(sender, permissions, std::string(),
                                base::FilePath(), profile_directory, true);
   browser_ppapi_host->set_plugin_process_handle(plugin_child_process);
 
   scoped_refptr<PepperMessageFilter> pepper_message_filter(
       new PepperMessageFilter());
-  channel->AddFilter(pepper_message_filter);
-  channel->AddFilter(browser_ppapi_host->message_filter().get());
-  channel->AddFilter(new TraceMessageFilter());
+  channel->AddFilter(pepper_message_filter->GetFilter());
+  channel->AddFilter(browser_ppapi_host->message_filter());
+  channel->AddFilter((new TraceMessageFilter())->GetFilter());
 
   return browser_ppapi_host;
 }
 
 BrowserPpapiHostImpl::BrowserPpapiHostImpl(
     IPC::Sender* sender,
     const ppapi::PpapiPermissions& permissions,
     const std::string& plugin_name,
     const base::FilePath& plugin_path,
     const base::FilePath& profile_data_directory,
@@ skipping 108 matching lines @@
   */
   return ppapi_host_->OnMessageReceived(msg);
 }
 
 void BrowserPpapiHostImpl::HostMessageFilter::OnHostDestroyed() {
   DCHECK(ppapi_host_);
   ppapi_host_ = NULL;
 }
 
 }  // namespace content