Mark template class RefCountedObject as final.

pc/test/mock_peerconnection.h

 /*
  *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef PC_TEST_MOCK_PEERCONNECTION_H_
 #define PC_TEST_MOCK_PEERCONNECTION_H_
 
 #include <vector>
 
 #include "call/call.h"
 #include "logging/rtc_event_log/rtc_event_log.h"
 #include "pc/peerconnection.h"
 #include "rtc_base/thread.h"
 #include "test/gmock.h"
 
 namespace webrtc {
 
 // The factory isn't really used; it just satisfies the base PeerConnection.
-class FakePeerConnectionFactory
-    : public rtc::RefCountedObject<webrtc::PeerConnectionFactory> {
+class FakePeerConnectionFactory : public webrtc::PeerConnectionFactory {
  public:
   FakePeerConnectionFactory()
-      : rtc::RefCountedObject<webrtc::PeerConnectionFactory>(
+      : webrtc::PeerConnectionFactory(
             rtc::Thread::Current(),
             rtc::Thread::Current(),
             rtc::Thread::Current(),
             nullptr,
             nullptr,
             nullptr,
             nullptr,
             nullptr,
             nullptr,
             std::unique_ptr<cricket::MediaEngineInterface>(),
             std::unique_ptr<webrtc::CallFactoryInterface>(),
             std::unique_ptr<RtcEventLogFactoryInterface>()) {}
 };
 
-class MockPeerConnection
-    : public rtc::RefCountedObject<webrtc::PeerConnection> {
+class MockPeerConnection : public webrtc::PeerConnection {
  public:
   MockPeerConnection()
-      : rtc::RefCountedObject<webrtc::PeerConnection>(
-            new FakePeerConnectionFactory(),
+      : webrtc::PeerConnection(
+            new rtc::RefCountedObject<FakePeerConnectionFactory>(),
             std::unique_ptr<RtcEventLog>(),
             std::unique_ptr<Call>()) {}
   MOCK_METHOD0(local_streams,
                rtc::scoped_refptr<StreamCollectionInterface>());
   MOCK_METHOD0(remote_streams,
                rtc::scoped_refptr<StreamCollectionInterface>());
   MOCK_METHOD0(session, WebRtcSession*());
   MOCK_CONST_METHOD0(GetSenders,
                      std::vector<rtc::scoped_refptr<RtpSenderInterface>>());
   MOCK_CONST_METHOD0(GetReceivers,
                      std::vector<rtc::scoped_refptr<RtpReceiverInterface>>());
   MOCK_CONST_METHOD0(sctp_data_channels,
                      const std::vector<rtc::scoped_refptr<DataChannel>>&());
 };
 
 }  // namespace webrtc
 
 #endif  // PC_TEST_MOCK_PEERCONNECTION_H_