Revert of Change the video color space default.

media/ffmpeg/ffmpeg_common.h

 // Copyright (c) 2012 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 MEDIA_FFMPEG_FFMPEG_COMMON_H_
 #define MEDIA_FFMPEG_FFMPEG_COMMON_H_
 
 // Used for FFmpeg error codes.
 #include <cerrno>
 
@@ skipping 99 matching lines @@
 // Converts FFmpeg's channel layout to chrome's ChannelLayout.  |channels| can
 // be used when FFmpeg's channel layout is not informative in order to make a
 // good guess about the plausible channel layout based on number of channels.
 MEDIA_EXPORT ChannelLayout ChannelLayoutToChromeChannelLayout(int64_t layout,
                                                               int channels);
 
 // Converts FFmpeg's audio sample format to Chrome's SampleFormat.
 MEDIA_EXPORT SampleFormat
     AVSampleFormatToSampleFormat(AVSampleFormat sample_format);
 
-// Converts FFmpeg's pixel format to its corresponding supported video format.
+// Converts FFmpeg's pixel formats to its corresponding supported video format.
 MEDIA_EXPORT VideoFrame::Format PixelFormatToVideoFormat(
     PixelFormat pixel_format);
 
-// Converts video formats to its corresponding FFmpeg pixel formats.
+// Converts video formats to its corresponding FFmpeg's pixel formats.
 PixelFormat VideoFormatToPixelFormat(VideoFrame::Format video_format);
 
-VideoFrame::ColorSpace AVColorSpaceToVideoFrameColorSpace(
-    AVColorSpace color_space);
-
 // Convert FFmpeg UTC representation (YYYY-MM-DD HH:MM:SS) to base::Time.
 // Returns true and sets |*out| if |date_utc| contains a valid
 // date string. Otherwise returns fals and timeline_offset is unmodified.
 MEDIA_EXPORT bool FFmpegUTCDateToTime(const char* date_utc, base::Time* out);
 
 }  // namespace media
 
 #endif  // MEDIA_FFMPEG_FFMPEG_COMMON_H_