Extract bitrate allocation of spatial/temporal layers out of codec impl.

webrtc/common_video/common_video.gyp

 # Copyright (c) 2012 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 51 matching lines @@
         'h264/pps_parser.h',
         'h264/sps_parser.cc',
         'h264/sps_parser.h',
         'i420_buffer_pool.cc',
         'video_frame.cc',
         'incoming_video_stream.cc',
         'include/bitrate_adjuster.h',
         'include/frame_callback.h',
         'include/i420_buffer_pool.h',
         'include/incoming_video_stream.h',
+        'include/video_bitrate_allocator.h',
         'include/video_frame_buffer.h',
         'libyuv/include/webrtc_libyuv.h',
         'libyuv/webrtc_libyuv.cc',
         'video_frame_buffer.cc',
         'video_render_frames.cc',
         'video_render_frames.h',
       ],
     },
   ],  # targets
 }