Added some missing includes, removed one include and removed an undef.

content/renderer/media/mock_data_channel_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_MEDIA_MOCK_DATA_CHANNEL_IMPL_H_
 #define CONTENT_RENDERER_MEDIA_MOCK_DATA_CHANNEL_IMPL_H_
 
 #include <string>
 
+#include "base/macros.h"
 #include "third_party/libjingle/source/talk/app/webrtc/peerconnectioninterface.h"
 
 namespace content {
 
 class MockDataChannel : public webrtc::DataChannelInterface {
  public:
   MockDataChannel(const std::string& label,
                   const webrtc::DataChannelInit* config);
 
   void RegisterObserver(webrtc::DataChannelObserver* observer) override;
@@ skipping 23 matching lines @@
   webrtc::DataChannelInterface::DataState state_;
   webrtc::DataChannelInit config_;
   webrtc::DataChannelObserver* observer_;
 
   DISALLOW_COPY_AND_ASSIGN(MockDataChannel);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MOCK_DATA_CHANNEL_IMPL_H_