Track buffered byte ranges correctly in media::Pipeline.

webkit/media/buffered_data_source.h

 // 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.
 
 #ifndef WEBKIT_MEDIA_BUFFERED_DATA_SOURCE_H_
 #define WEBKIT_MEDIA_BUFFERED_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 147 matching lines @@
   scoped_ptr<BufferedResourceLoader> loader_;
 
   // True if |loader| is downloading data.
   bool is_downloading_data_;
 
   // Callback method from the pipeline for initialization.
   media::PipelineStatusCB initialize_cb_;
 
   // Read parameters received from the Read() method call.
   media::DataSource::ReadCB read_cb_;
-  int64 read_position_;
   int read_size_;
   uint8* read_buffer_;
+  // Retained between reads to make sense of buffering information.
+  int64 last_read_start_;
 
   // This buffer is intermediate, we use it for BufferedResourceLoader to write
   // to. And when read in BufferedResourceLoader is done, we copy data from
   // this buffer to |read_buffer_|. The reason for an additional copy is that
   // we don't own |read_buffer_|. But since the read operation is asynchronous,
   // |read_buffer| can be destroyed at any time, so we only copy into
   // |read_buffer| in the final step when it is safe.
   // Memory is allocated for this member during initialization of this object
   // because we want buffer to be passed into BufferedResourceLoader to be
   // always non-null. And by initializing this member with a default size we can
@@ skipping 34 matching lines @@
   float playback_rate_;
 
   scoped_refptr<media::MediaLog> media_log_;
 
   DISALLOW_COPY_AND_ASSIGN(BufferedDataSource);
 };
 
 }  // namespace webkit_media
 
 #endif  // WEBKIT_MEDIA_BUFFERED_DATA_SOURCE_H_