Enable the -Wundef warning for clang

webrtc/modules/audio_coding/neteq/decoder_database_unittest.cc

 /*
  *  Copyright (c) 2012 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/modules/audio_coding/neteq/decoder_database.h"
 
 #include <assert.h>
 #include <stdlib.h>
 
 #include <string>
 
-#include "testing/gmock/include/gmock/gmock.h"
-#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/gmock.h"
+#include "webrtc/base/gtest.h"
 
 #include "webrtc/modules/audio_coding/neteq/mock/mock_audio_decoder.h"
 #include "webrtc/modules/audio_coding/codecs/builtin_audio_decoder_factory.h"
 #include "webrtc/modules/audio_coding/codecs/mock/mock_audio_decoder_factory.h"
 
 using testing::_;
 using testing::Invoke;
 
 namespace webrtc {
 
@@ skipping 234 matching lines @@
   EXPECT_EQ(DecoderDatabase::kOK, db.Remove(13));
   EXPECT_EQ(NULL, db.GetActiveCngDecoder());
 
   // Try to set non-existing codecs as active.
   EXPECT_EQ(DecoderDatabase::kDecoderNotFound,
             db.SetActiveDecoder(17, &changed));
   EXPECT_EQ(DecoderDatabase::kDecoderNotFound,
             db.SetActiveCngDecoder(17));
 }
 }  // namespace webrtc