Consolidate and improve audio decoding test for all decoders.

media/filters/audio_file_reader.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/audio_file_reader.h"
 
 #include <cmath>
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 239 matching lines @@
     // Skip packets from other streams.
     if (output_packet->stream_index != stream_index_) {
       av_free_packet(output_packet);
       continue;
     }
     return true;
   }
   return false;
 }
 
+bool AudioFileReader::SeekForTesting(base::TimeDelta seek_time) {
+  return av_seek_frame(glue_->format_context(),
+                       stream_index_,
+                       ConvertToTimeBase(codec_context_->time_base, seek_time),
+                       AVSEEK_FLAG_BACKWARD) >= 0;
+}
+
 }  // namespace media