Enable the -Wundef warning for clang

webrtc/test/direct_transport.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.
  */
 #include "webrtc/test/direct_transport.h"
 
-#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/test/gtest.h"
 
 #include "webrtc/call.h"
 #include "webrtc/system_wrappers/include/clock.h"
 
 namespace webrtc {
 namespace test {
 
 DirectTransport::DirectTransport(Call* send_call)
     : DirectTransport(FakeNetworkPipe::Config(), send_call) {}
 
@@ skipping 59 matching lines @@
   fake_network_.Process();
   int64_t wait_time_ms = fake_network_.TimeUntilNextProcess();
   if (wait_time_ms > 0) {
     packet_event_.Wait(static_cast<int>(wait_time_ms));
   }
   rtc::CritScope crit(&lock_);
   return shutting_down_ ? false : true;
 }
 }  // namespace test
 }  // namespace webrtc