Revert of Delete unused file mediacommon.h.

webrtc/media/media.gyp

 # Copyright (c) 2016 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.
 
 {
   'includes': [ '../build/common.gypi', ],
@@ skipping 17 matching lines @@
       'sources': [
         'base/adaptedvideotracksource.cc',
         'base/adaptedvideotracksource.h',
         'base/audiosource.h',
         'base/codec.cc',
         'base/codec.h',
         'base/cryptoparams.h',
         'base/device.h',
         'base/hybriddataengine.h',
         'base/mediachannel.h',
+        'base/mediacommon.h',
         'base/mediaconstants.cc',
         'base/mediaconstants.h',
         'base/mediaengine.cc',
         'base/mediaengine.h',
         'base/rtpdataengine.cc',
         'base/rtpdataengine.h',
         'base/rtpdump.cc',
         'base/rtpdump.h',
         'base/rtputils.cc',
         'base/rtputils.h',
@@ skipping 114 matching lines @@
                 'gdi32.lib',
                 'strmiids.lib',
               ],
             },
           },
         }],
       ],
     },  # target rtc_media
   ],  # targets.
 }