MSE: Fix logic bugs with high precision duration

media/filters/chunk_demuxer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/chunk_demuxer.h"
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 
@@ skipping 1190 matching lines @@
   DCHECK_NE(state_, SHUTDOWN);
   host_->AddTextStream(text_stream, config);
 }
 
 bool ChunkDemuxer::IsValidId(const std::string& source_id) const {
   lock_.AssertAcquired();
   return source_state_map_.count(source_id) > 0u;
 }
 
 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);
 }
 
 void ChunkDemuxer::IncreaseDurationIfNecessary(TimeDelta new_duration) {
   DCHECK(new_duration != kNoTimestamp);
   DCHECK(new_duration != kInfiniteDuration);
 
   // Per April 1, 2014 MSE spec editor's draft:
@@ skipping 19 matching lines @@
 
   for (auto itr = source_state_map_.begin(); itr != source_state_map_.end();
        ++itr) {
     max_duration = std::max(max_duration,
                             itr->second->GetMaxBufferedDuration());
   }
 
   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 {
   base::AutoLock auto_lock(lock_);
   return GetBufferedRanges_Locked();
 }
 
 Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges_Locked() const {
   lock_.AssertAcquired();
 
@@ skipping 38 matching lines @@
 }
 
 void ChunkDemuxer::ShutdownAllStreams() {
   for (auto itr = source_state_map_.begin(); itr != source_state_map_.end();
        ++itr) {
     itr->second->Shutdown();
   }
 }
 
 }  // namespace media