Enable the -Wundef warning for clang

webrtc/video/video_quality_test.cc

 /*
  *  Copyright (c) 2015 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.
  */
 #include "webrtc/video/video_quality_test.h"
 
 #include <stdio.h>
 #include <algorithm>
 #include <deque>
 #include <map>
 #include <sstream>
 #include <string>
 #include <vector>
 
-#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/gtest.h"
 #include "webrtc/base/checks.h"
 #include "webrtc/base/event.h"
 #include "webrtc/base/format_macros.h"
 #include "webrtc/base/optional.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/call.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_header_parser.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 #include "webrtc/system_wrappers/include/cpu_info.h"
@@ skipping 1325 matching lines @@
      call->DestroyAudioSendStream(audio_send_stream_);
      call->DestroyAudioReceiveStream(audio_receive_stream);
   }
 
   transport.StopSending();
   if (params_.audio)
     DestroyVoiceEngine(&voe);
 }
 
 }  // namespace webrtc