Enable the -Wundef warning for clang

webrtc/tools/frame_analyzer/video_quality_analysis_unittest.cc

 /*
  *  Copyright (c) 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.
  */
 
 // This test doesn't actually verify the output since it's just printed
 // to stdout by void functions, but it's still useful as it executes the code.
 
 #include <fstream>
 #include <string>
 
-#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/test/gtest.h"
 #include "webrtc/test/testsupport/fileutils.h"
 #include "webrtc/tools/frame_analyzer/video_quality_analysis.h"
 
 namespace webrtc {
 namespace test {
 
 // Setup a log file to write the output to instead of stdout because we don't
 // want those numbers to be picked up as perf numbers.
 class VideoQualityAnalysisTest : public ::testing::Test {
  protected:
@@ skipping 54 matching lines @@
   stats_file << "frame_0003 0101\n";
   stats_file << "frame_0004 0106\n";
   stats_file.close();
 
   PrintMaxRepeatedAndSkippedFrames(logfile_, "NormalStatsFile", stats_filename);
 }
 
 
 }  // namespace test
 }  // namespace webrtc