Mark template class RefCountedObject as final.

pc/test/mock_peerconnection.h

Index: pc/test/mock_peerconnection.h
diff --git a/pc/test/mock_peerconnection.h b/pc/test/mock_peerconnection.h
index e4343fff619debd502ddb6612990b4ef7b2552c0..1c0a4355f57e9098fae260237336159231621edd 100644
--- a/pc/test/mock_peerconnection.h
+++ b/pc/test/mock_peerconnection.h
@@ -22,11 +22,10 @@
 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(),
@@ -41,12 +40,11 @@ class FakePeerConnectionFactory
             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,