media: Introduce DemuxerStreamProvider interface.

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index 15b6a51fb17b2c77149aa883d4d802f85bca940a..1a874f8685c400b7c866833966a93f5a1d40fbbc 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -649,6 +649,10 @@ void FFmpegDemuxer::Initialize(DemuxerHost* host,
                  status_cb));
 }
 
+base::Time FFmpegDemuxer::GetTimelineOffset() const {
+  return timeline_offset_;
+}
+
 DemuxerStream* FFmpegDemuxer::GetStream(DemuxerStream::Type type) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return GetFFmpegStream(type);
@@ -665,10 +669,6 @@ FFmpegDemuxerStream* FFmpegDemuxer::GetFFmpegStream(
   return NULL;
 }
 
-base::Time FFmpegDemuxer::GetTimelineOffset() const {
-  return timeline_offset_;
-}
-
 Demuxer::Liveness FFmpegDemuxer::GetLiveness() const {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return liveness_;