Reland of Work on flexible mode and screen sharing.

webrtc/modules/video_coding/codecs/vp9/vp9.gyp

 # Copyright (c) 2014 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': [
@@ skipping 10 matching lines @@
       ],
       'conditions': [
         ['build_libvpx==1', {
           'dependencies': [
             '<(libvpx_dir)/libvpx.gyp:libvpx_new',
           ],
         }],
         ['build_vp9==1', {
           'sources': [
             'include/vp9.h',
+            'screenshare_layers.cc',
+            'screenshare_layers.h',
             'vp9_frame_buffer_pool.cc',
             'vp9_frame_buffer_pool.h',
             'vp9_impl.cc',
             'vp9_impl.h',
           ],
         }, {
           'sources': [
             'vp9_dummy_impl.cc',
           ],
         }],
       ],
     },
   ],
 }