Update WebMClusterParser to compute durations for all StreamParserBuffers.

media/base/stream_parser_buffer.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/base/stream_parser_buffer.h"
 
 #include "base/logging.h"
 
 namespace media {
 
 StreamParserBuffer::StreamParserBuffer(const uint8* data, int data_size,
                                        bool is_keyframe)
     : DataBuffer(data, data_size),
       is_keyframe_(is_keyframe) {
+  SetDuration(kNoTimestamp());
 }
 
 scoped_refptr<StreamParserBuffer> StreamParserBuffer::CreateEOSBuffer() {
   return make_scoped_refptr(new StreamParserBuffer(NULL, 0, false));
 }
 
 scoped_refptr<StreamParserBuffer> StreamParserBuffer::CopyFrom(
     const uint8* data, int data_size, bool is_keyframe) {
   return make_scoped_refptr(
       new StreamParserBuffer(data, data_size, is_keyframe));
 }
 
 base::TimeDelta StreamParserBuffer::GetEndTimestamp() const {
   DCHECK(GetTimestamp() != kNoTimestamp());
   DCHECK(GetDuration() != kNoTimestamp());
   return GetTimestamp() + GetDuration();
 }
 
 }  // namespace media