Allow MessageFilters to restrict listening to specific message classes

content/browser/renderer_host/media/peer_connection_tracker_host.cc

 // Copyright (c) 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.
 #include "content/browser/renderer_host/media/peer_connection_tracker_host.h"
 
 #include "content/browser/media/webrtc_internals.h"
 #include "content/common/media/peer_connection_tracker_messages.h"
 
 namespace content {
 
 PeerConnectionTrackerHost::PeerConnectionTrackerHost(int render_process_id)
-    : render_process_id_(render_process_id) {}
+    : BrowserMessageFilter(PeerConnectionTrackerMsgStart),
+      render_process_id_(render_process_id) {}
 
 bool PeerConnectionTrackerHost::OnMessageReceived(const IPC::Message& message,
                                                   bool* message_was_ok) {
   bool handled = true;
 
   IPC_BEGIN_MESSAGE_MAP_EX(PeerConnectionTrackerHost, message, *message_was_ok)
     IPC_MESSAGE_HANDLER(PeerConnectionTrackerHost_AddPeerConnection,
                         OnAddPeerConnection)
     IPC_MESSAGE_HANDLER(PeerConnectionTrackerHost_RemovePeerConnection,
                         OnRemovePeerConnection)
@@ skipping 53 matching lines @@
   WebRTCInternals::GetInstance()->OnGetUserMedia(render_process_id_,
                                                  peer_pid(),
                                                  origin,
                                                  audio,
                                                  video,
                                                  audio_constraints,
                                                  video_constraints);
 }
 
 }  // namespace content