WebRTC: Fix and enable -Woverloaded-virtual warnings.

webrtc/api/test/peerconnectiontestwrapper.h

 /*
  *  Copyright 2013 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 WEBRTC_API_TEST_PEERCONNECTIONTESTWRAPPER_H_
 #define WEBRTC_API_TEST_PEERCONNECTIONTESTWRAPPER_H_
 
 #include <memory>
 
 #include "webrtc/api/peerconnectioninterface.h"
 #include "webrtc/api/test/fakeaudiocapturemodule.h"
 #include "webrtc/api/test/fakeconstraints.h"
 #include "webrtc/api/test/fakevideotrackrenderer.h"
 #include "webrtc/base/sigslot.h"
 
 class PeerConnectionTestWrapper
     : public webrtc::PeerConnectionObserver,
       public webrtc::CreateSessionDescriptionObserver,
       public sigslot::has_slots<> {
  public:
+  // We need these using declarations because there are two versions of each of
+  // the below methods and we only override one of them.
+  // TODO(deadbeef): Remove once there's only one version of the methods.
+  using PeerConnectionObserver::OnAddStream;
+  using PeerConnectionObserver::OnRemoveStream;
+  using PeerConnectionObserver::OnDataChannel;
+
   static void Connect(PeerConnectionTestWrapper* caller,
                       PeerConnectionTestWrapper* callee);
 
   PeerConnectionTestWrapper(const std::string& name,
                             rtc::Thread* network_thread,
                             rtc::Thread* worker_thread);
   virtual ~PeerConnectionTestWrapper();
 
   bool CreatePc(
       const webrtc::MediaConstraintsInterface* constraints,
@@ skipping 63 matching lines @@
   rtc::Thread* const network_thread_;
   rtc::Thread* const worker_thread_;
   rtc::scoped_refptr<webrtc::PeerConnectionInterface> peer_connection_;
   rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface>
       peer_connection_factory_;
   rtc::scoped_refptr<FakeAudioCaptureModule> fake_audio_capture_module_;
   std::unique_ptr<webrtc::FakeVideoTrackRenderer> renderer_;
 };
 
 #endif  // WEBRTC_API_TEST_PEERCONNECTIONTESTWRAPPER_H_