Enable the -Wundef warning for clang

webrtc/call/packet_injection_tests.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 <memory>
 
-#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/gtest.h"
 

[kjellander_webrtc, 2016/09/23 12:32:37]

remove blank line?

 #include "webrtc/test/call_test.h"
 #include "webrtc/test/null_transport.h"
 
 namespace webrtc {
 
 class PacketInjectionTest : public test::CallTest {
  protected:
   enum class CodecType {
     kVp8,
     kH264,
@@ skipping 59 matching lines @@
                              0xED,
                              0x58,
                              0xCB,
                              0xED,
                              0xDF};
 
   InjectIncorrectPacket(CodecType::kH264, 101, kPacket, sizeof(kPacket));
 }
 
 }  // namespace webrtc