Use of the playback time in the MSE garbage collection.

media/filters/source_buffer_stream.cc

Index: media/filters/source_buffer_stream.cc
diff --git a/media/filters/source_buffer_stream.cc b/media/filters/source_buffer_stream.cc
index faba8ec9d1e8d75832cd3ce30296e4c7b766397a..9fc731f1299fac8a46d119d7863efc80ca0f5cf9 100644
--- a/media/filters/source_buffer_stream.cc
+++ b/media/filters/source_buffer_stream.cc
@@ -103,6 +103,7 @@ SourceBufferStream::SourceBufferStream(const AudioDecoderConfig& audio_config,
       end_of_stream_(false),
       seek_buffer_timestamp_(kNoTimestamp()),
       selected_range_(NULL),
+      current_media_time_(kNoDecodeTimestamp()),
       media_segment_start_time_(kNoDecodeTimestamp()),
       range_for_next_append_(ranges_.end()),
       new_media_segment_(false),
@@ -129,6 +130,7 @@ SourceBufferStream::SourceBufferStream(const VideoDecoderConfig& video_config,
       end_of_stream_(false),
       seek_buffer_timestamp_(kNoTimestamp()),
       selected_range_(NULL),
+      current_media_time_(kNoDecodeTimestamp()),
       media_segment_start_time_(kNoDecodeTimestamp()),
       range_for_next_append_(ranges_.end()),
       new_media_segment_(false),
@@ -156,6 +158,7 @@ SourceBufferStream::SourceBufferStream(const TextTrackConfig& text_config,
       end_of_stream_(false),
       seek_buffer_timestamp_(kNoTimestamp()),
       selected_range_(NULL),
+      current_media_time_(kNoDecodeTimestamp()),
       media_segment_start_time_(kNoDecodeTimestamp()),
       range_for_next_append_(ranges_.end()),
       new_media_segment_(false),
@@ -707,6 +710,10 @@ int SourceBufferStream::FreeBuffers(int total_bytes_to_free,
         DCHECK_EQ(current_range, selected_range_);
         break;
       }
+      if (current_media_time_ != kNoDecodeTimestamp() &&
+          !current_range->FirstGOPEarlierThanMediaTime(current_media_time_)) {
+        break;
+      }
       bytes_deleted = current_range->DeleteGOPFromFront(&buffers);
     }
 
@@ -884,11 +891,23 @@ void SourceBufferStream::MergeWithAdjacentRangeIfNecessary(
   DeleteAndRemoveRange(&next_range_itr);
 }
 
+void SourceBufferStream::NotifyMediaTimeUpdate(DecodeTimestamp media_time) {
+  if (current_media_time_ != kNoDecodeTimestamp() &&
+      media_time < current_media_time_) {
+    DLOG(WARNING) << "Time should be monotonically increasing: "
+                  << media_time.InMilliseconds()
+                  << " " << current_media_time_.InMilliseconds();
+    return;
+  }
+  current_media_time_ = media_time;
+}
+
 void SourceBufferStream::Seek(base::TimeDelta timestamp) {
   DCHECK(timestamp >= base::TimeDelta());
   DVLOG(1) << __FUNCTION__ << " " << GetStreamTypeName()
            << " (" << timestamp.InSecondsF() << ")";
   ResetSeekState();
+  current_media_time_ = kNoDecodeTimestamp();
 
   if (ShouldSeekToStartOfBuffered(timestamp)) {
     ranges_.front()->SeekToStart();