Implement evictFrames() to support MSE's coded frame eviction algorithm.

media/filters/chunk_demuxer.h

Index: media/filters/chunk_demuxer.h
diff --git a/media/filters/chunk_demuxer.h b/media/filters/chunk_demuxer.h
index 6e8bdf95c7cde7cd6e767cf9c7b862f0ec0ec1fc..abb367da28490a9919085620a914914128d834bc 100644
--- a/media/filters/chunk_demuxer.h
+++ b/media/filters/chunk_demuxer.h
@@ -56,6 +56,13 @@ class MEDIA_EXPORT ChunkDemuxerStream : public DemuxerStream {
   void Remove(base::TimeDelta start, base::TimeDelta end,
               base::TimeDelta duration);
 
+  // If the buffer is full, runs Frame Removal to try to free up space, as
+  // specified in the "Coded Frame Eviction Algorithm" in the Media Source
+  // Extensions Spec. Returns false iff buffer is still full after running
+  // eviction
+  // https://w3c.github.io/media-source/#sourcebuffer-coded-frame-eviction
+  bool EvictFrames(DecodeTimestamp media_time);
+
   // Signal to the stream that duration has changed to |duration|.
   void OnSetDuration(base::TimeDelta duration);
 
@@ -163,6 +170,11 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
                bool splice_frames_enabled);
   ~ChunkDemuxer() override;
 
+  // Set the media time provider.
+  // TODO(damienv): should truly be part of the constructor.
+  void SetMediaTimeProvider(
+      const base::Callback<base::TimeDelta(void)>& get_media_time_cb);
+
   // Demuxer implementation.
   void Initialize(DemuxerHost* host,
                   const PipelineStatusCB& cb,
@@ -242,6 +254,8 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   void Remove(const std::string& id, base::TimeDelta start,
               base::TimeDelta end);
 
+  bool EvictFrames();
+
   // Returns the current presentation duration.
   double GetDuration();
   double GetDuration_Locked();
@@ -376,6 +390,8 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   scoped_ptr<ChunkDemuxerStream> audio_;
   scoped_ptr<ChunkDemuxerStream> video_;
 
+  base::Callback<base::TimeDelta(void)> get_media_time_cb_;
+
   base::TimeDelta duration_;
 
   // The duration passed to the last SetDuration(). If