[cast_channel] Make CastSocketService a global leaky singleton

components/cast_channel/cast_socket.cc

 // Copyright 2014 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 "components/cast_channel/cast_socket.h"
 
 #include <stdlib.h>
 #include <string.h>
 
 #include <utility>
@@ skipping 278 matching lines @@
 CastTransport* CastSocketImpl::transport() const {
   return transport_.get();
 }
 
 void CastSocketImpl::AddObserver(Observer* observer) {
   DCHECK(observer);
   if (!observers_.HasObserver(observer))
     observers_.AddObserver(observer);
 }
 
+void CastSocketImpl::RemoveObserver(Observer* observer) {
+  DCHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
 void CastSocketImpl::OnConnectTimeout() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   // Stop all pending connection setup tasks and report back to the client.
   is_canceled_ = true;
   VLOG_WITH_CONNECTION(1) << "Timeout while establishing a connection.";
   SetErrorState(ChannelError::CONNECT_TIMEOUT);
   DoConnectCallback();
 }
 
 void CastSocketImpl::ResetConnectLoopCallback() {
@@ skipping 336 matching lines @@
 void CastSocketImpl::CastSocketMessageDelegate::OnMessage(
     const CastMessage& message) {
   for (auto& observer : socket_->observers_)
     observer.OnMessage(*socket_, message);
 }
 
 void CastSocketImpl::CastSocketMessageDelegate::Start() {}
 
 }  // namespace cast_channel
 #undef VLOG_WITH_CONNECTION