Enable the -Wundef warning for clang

webrtc/modules/audio_coding/neteq/mock/mock_expand.h

 /*
  *  Copyright (c) 2014 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_MODULES_AUDIO_CODING_NETEQ_MOCK_MOCK_EXPAND_H_
 #define WEBRTC_MODULES_AUDIO_CODING_NETEQ_MOCK_MOCK_EXPAND_H_
 
 #include "webrtc/modules/audio_coding/neteq/expand.h"
 
-#include "testing/gmock/include/gmock/gmock.h"
+#include "webrtc/test/gmock.h"
 
 namespace webrtc {
 
 class MockExpand : public Expand {
  public:
   MockExpand(BackgroundNoise* background_noise,
              SyncBuffer* sync_buffer,
              RandomVector* random_vector,
              StatisticsCalculator* statistics,
              int fs,
@@ skipping 28 matching lines @@
                      Expand*(BackgroundNoise* background_noise,
                              SyncBuffer* sync_buffer,
                              RandomVector* random_vector,
                              StatisticsCalculator* statistics,
                              int fs,
                              size_t num_channels));
 };
 
 }  // namespace webrtc
 #endif  // WEBRTC_MODULES_AUDIO_CODING_NETEQ_MOCK_MOCK_EXPAND_H_