Improving WebM video duration estimation.

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 fb699dbad5e85739b306751898c644c62013b64b..4271ab9601bb44393a6f79f0db3fd09daf7c00fd 100644
--- a/media/filters/source_buffer_stream.cc
+++ b/media/filters/source_buffer_stream.cc
@@ -337,6 +337,11 @@ bool SourceBufferStream::Append(const BufferQueue& buffers) {
 
     track_buffer_.insert(track_buffer_.end(), deleted_buffers.begin(),
                          deleted_buffers.end());
+    DVLOG(3) << __FUNCTION__ << " Added " << deleted_buffers.size()
+             << " deleted buffers to track buffer. TB size is now "
+             << track_buffer_.size();
+  } else {
+    DVLOG(3) << __FUNCTION__ << " No deleted buffers for track buffer";
   }
 
   // Prune any extra buffers in |track_buffer_| if new keyframes
@@ -824,11 +829,14 @@ void SourceBufferStream::PrepareRangesForNextAppend(
   DecodeTimestamp end = new_buffers.back()->GetDecodeTimestamp();
   base::TimeDelta duration = new_buffers.back()->duration();
 
-  if (duration != kNoTimestamp() && duration > base::TimeDelta()) {
+  // Set end time for remove to include the duration of last buffer. If the
+  // duration is estimated, use 1 microsecond instead to ensure frames are not
+  // accidentally removed due to over-estimation.
+  if (duration != kNoTimestamp() && duration > base::TimeDelta() &&
+      !new_buffers.back()->is_duration_estimated()) {
     end += duration;
   } else {
-    // TODO(acolwell): Ensure all buffers actually have proper
-    // duration info so that this hack isn't needed.
+    // TODO(chcunningham): Emit warning when 0ms durations are not expected.
     // http://crbug.com/312836
     end += base::TimeDelta::FromInternalValue(1);
   }
@@ -1077,6 +1085,7 @@ SourceBufferStream::Status SourceBufferStream::GetNextBufferInternal(
       return kConfigChange;
     }
 
+    DVLOG(3) << __FUNCTION__ << " Next buffer coming from track_buffer_";
     *out_buffer = next_buffer;
     track_buffer_.pop_front();
     last_output_buffer_timestamp_ = (*out_buffer)->GetDecodeTimestamp();