Switch to AVIO instead of a custom FFmpeg URLProtocol handler.

media/ffmpeg/ffmpeg_common.cc

Index: media/ffmpeg/ffmpeg_common.cc
diff --git a/media/ffmpeg/ffmpeg_common.cc b/media/ffmpeg/ffmpeg_common.cc
index 6820066e52b250350025373e0045e3d019e4ebf3..e487c4948ced3acc5a2c66f4f9a5d9f480cc9eed 100644
--- a/media/ffmpeg/ffmpeg_common.cc
+++ b/media/ffmpeg/ffmpeg_common.cc
@@ -413,30 +413,4 @@ PixelFormat VideoFormatToPixelFormat(VideoFrame::Format video_format) {
   return PIX_FMT_NONE;
 }
 
-void DestroyAVFormatContext(AVFormatContext* format_context) {
-  DCHECK(format_context);
-
-  // Iterate each stream and destroy each one of them.
-  if (format_context->streams) {
-    int streams = format_context->nb_streams;
-    for (int i = 0; i < streams; ++i) {
-      AVStream* stream = format_context->streams[i];
-
-      // The conditions for calling avcodec_close():
-      // 1. AVStream is alive.
-      // 2. AVCodecContext in AVStream is alive.
-      // 3. AVCodec in AVCodecContext is alive.
-      // Notice that closing a codec context without prior avcodec_open2() will
-      // result in a crash in FFmpeg.
-      if (stream && stream->codec && stream->codec->codec) {
-        stream->discard = AVDISCARD_ALL;
-        avcodec_close(stream->codec);
-      }
-    }
-  }
-
-  // Then finally cleanup the format context.
-  avformat_close_input(&format_context);
-}
-
 }  // namespace media