MSE: Fix logic bugs with high precision duration

media/filters/chunk_demuxer.cc

Index: media/filters/chunk_demuxer.cc
diff --git a/media/filters/chunk_demuxer.cc b/media/filters/chunk_demuxer.cc
index b7c4ca5be3be6c19410636cb2e36db1ff03c3deb..c0fb132b462e23d25b7c4f1907adacc51a843ff3 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -1208,7 +1208,8 @@ bool ChunkDemuxer::IsValidId(const std::string& source_id) const {
 }
 
 void ChunkDemuxer::UpdateDuration(TimeDelta new_duration) {
-  DCHECK(duration_ != new_duration);
+  DCHECK(duration_ != new_duration ||
+         user_specified_duration_ != new_duration.InSecondsF());
   user_specified_duration_ = -1;
   duration_ = new_duration;
   host_->SetDuration(new_duration);
@@ -1248,8 +1249,12 @@ void ChunkDemuxer::DecreaseDurationIfNecessary() {
   if (max_duration.is_zero())
     return;
 
-  if (max_duration < duration_)
+  // Note: be careful to also check |user_specified_duration_|, which may have
+  // higher precision than |duration_|.
+  if (max_duration < duration_ ||
+      max_duration.InSecondsF() < user_specified_duration_) {

[wolenetz, 2016/12/16 00:56:51]

good !!

[chcunningham, 2017/01/03 17:48:05]

Acknowledged.

     UpdateDuration(max_duration);
+  }
 }
 
 Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges() const {