Shutdown PeerConnectionDependencyFactory before Blink shutdown

content/renderer/media/webrtc/peer_connection_dependency_factory.cc

Index: content/renderer/media/webrtc/peer_connection_dependency_factory.cc
diff --git a/content/renderer/media/webrtc/peer_connection_dependency_factory.cc b/content/renderer/media/webrtc/peer_connection_dependency_factory.cc
index 6c886e9df99fe47426fcb0300faf83ef840023d5..a1ecf0d9459c9f1818bcec6112017335d370b515 100644
--- a/content/renderer/media/webrtc/peer_connection_dependency_factory.cc
+++ b/content/renderer/media/webrtc/peer_connection_dependency_factory.cc
@@ -148,10 +148,6 @@ PeerConnectionDependencyFactory::GetPcFactory() {
   return pc_factory_;
 }
 
-void PeerConnectionDependencyFactory::WillDestroyCurrentMessageLoop() {
-  CleanupPeerConnectionFactory();
-}
-
 void PeerConnectionDependencyFactory::CreatePeerConnectionFactory() {
   DCHECK(!pc_factory_.get());
   DCHECK(!signaling_thread_);
@@ -175,7 +171,6 @@ void PeerConnectionDependencyFactory::CreatePeerConnectionFactory() {
   }
 #endif
 
-  base::MessageLoop::current()->AddDestructionObserver(this);
   // To allow sending to the signaling/worker threads.
   jingle_glue::JingleThreadWrapper::EnsureForCurrentMessageLoop();
   jingle_glue::JingleThreadWrapper::current()->set_send_allowed(true);
@@ -281,6 +276,10 @@ void PeerConnectionDependencyFactory::InitializeSignalingThread(
   event->Signal();
 }
 
+void PeerConnectionDependencyFactory::ShutDown() {
+  CleanupPeerConnectionFactory();
+}
+
 bool PeerConnectionDependencyFactory::PeerConnectionFactoryCreated() {
   return pc_factory_.get() != NULL;
 }