[cast_channel] Make CastSocketService a global leaky singleton

components/cast_channel/cast_socket_service_unittest.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_service.h"
 #include "base/test/mock_callback.h"
 #include "components/cast_channel/cast_test_util.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 
 #include "testing/gmock/include/gmock/gmock.h"
@@ skipping 16 matching lines @@
         cast_socket_service_(new CastSocketService()) {}
 
   CastSocket* AddSocket(std::unique_ptr<CastSocket> socket) {
     return cast_socket_service_->AddSocket(std::move(socket));
   }
 
   void TearDown() override { cast_socket_service_ = nullptr; }
 
  protected:
   content::TestBrowserThreadBundle thread_bundle_;
-  scoped_refptr<CastSocketService> cast_socket_service_;
+  std::unique_ptr<CastSocketService> cast_socket_service_;
   base::MockCallback<CastSocket::OnOpenCallback> mock_on_open_callback_;
   MockCastSocketObserver mock_observer_;
 };
 
 TEST_F(CastSocketServiceTest, TestAddSocket) {
   auto socket1 = base::MakeUnique<MockCastSocket>();
   auto* socket_ptr1 = AddSocket(std::move(socket1));
   EXPECT_NE(0, socket_ptr1->id());
 
   auto socket2 = base::MakeUnique<MockCastSocket>();
@@ skipping 39 matching lines @@
           })));
   EXPECT_CALL(mock_on_open_callback_, Run(_, ChannelError::NONE));
   EXPECT_CALL(*mock_socket, AddObserver(_));
 
   cast_socket_service_->OpenSocket(ip_endpoint, nullptr /* net_log */,
                                    mock_on_open_callback_.Get(),
                                    &mock_observer_);
 }
 
 }  // namespace cast_channel