Update SourceBufferStream and its unit tests to always expect valid durations.

media/filters/ffmpeg_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/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/base64.h"
@@ skipping 260 matching lines @@
           audio_decoder_config().samples_per_second();
       buffer->set_discard_padding(std::make_pair(
           FramesToTimeDelta(discard_front_samples, samples_per_second),
           FramesToTimeDelta(discard_end_samples, samples_per_second)));
     }
 
     if (decrypt_config)
       buffer->set_decrypt_config(decrypt_config.Pass());
   }
 
-  buffer->set_duration(
-      ConvertStreamTimestamp(stream_->time_base, packet->duration));
+  if (packet->duration >= 0) {
+    buffer->set_duration(
+        ConvertStreamTimestamp(stream_->time_base, packet->duration));
+  } else {
+    DVLOG(1) << "FFmpeg returned a buffer with a negative duration! "

[acolwell GONE FROM CHROMIUM, 2014/07/16 18:17:46]

Filed https://code.google.com/p/chromium/issues/detail?id=394418 to track down
why FFmpeg is doing this.

[wolenetz, 2014/07/16 19:51:03]

nit: That bug is irksome. Please add a TODO(wolenetz) here referencing that bug;
I think I'll take a look at this during some upcoming ffmpeg work.

[acolwell GONE FROM CHROMIUM, 2014/07/16 19:54:55]

Done.

+             << packet->duration;
+    buffer->set_duration(kNoTimestamp());
+  }
 
   // Note: If pts is AV_NOPTS_VALUE, stream_timestamp will be kNoTimestamp().
   const base::TimeDelta stream_timestamp =
       ConvertStreamTimestamp(stream_->time_base, packet->pts);
 
   if (stream_timestamp != kNoTimestamp()) {
     // If this is an OGG file with negative timestamps don't rebase any other
     // stream types against the negative starting time.
     base::TimeDelta start_time = demuxer_->start_time();
     if (fixup_negative_ogg_timestamps_ && type() != AUDIO &&
@@ skipping 904 matching lines @@
   }
   for (size_t i = 0; i < buffered.size(); ++i)
     host_->AddBufferedTimeRange(buffered.start(i), buffered.end(i));
 }
 
 void FFmpegDemuxer::OnDataSourceError() {
   host_->OnDemuxerError(PIPELINE_ERROR_READ);
 }
 
 }  // namespace media