Demuxer stream now uses a callback instead of Assignable template. Cleaning ...

media/base/filters.h

 // Copyright (c) 2006-2009 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.
 
 // Filters are connected in a strongly typed manner, with downstream filters
 // always reading data from upstream filters.  Upstream filters have no clue
 // who is actually reading from them, and return the results via OnAssignment
 // using the AssignableInterface<SomeBufferType> interface:
 //
 //                         DemuxerStream(Video) <- VideoDecoder <- VideoRenderer
@@ skipping 11 matching lines @@
 // use the scheduler to signal errors and shutdown playback.
 
 #ifndef MEDIA_BASE_FILTERS_H_
 #define MEDIA_BASE_FILTERS_H_
 
 #include <limits>
 #include <string>
 
 #include "base/logging.h"
 #include "base/ref_counted.h"
+#include "base/task.h"
 #include "base/time.h"
 #include "media/base/media_format.h"
 
 namespace media {
 
 template <class TBuffer> class Assignable;
 class Buffer;
 class Decoder;
 class DemuxerStream;
 class FilterHost;
@@ skipping 107 matching lines @@
   // Returns the stream for the given index, NULL otherwise
   virtual scoped_refptr<DemuxerStream> GetStream(int stream_id) = 0;
 };
 
 
 class DemuxerStream : public base::RefCountedThreadSafe<DemuxerStream> {
  public:
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat& media_format() = 0;
 
-  // Schedules a read and takes ownership of the given buffer.
-  virtual void Read(Assignable<Buffer>* buffer) = 0;
+  // Schedules a read.  When the |read_callback| is called, the downstream
+  // filter takes ownership of the buffer by AddRef()'ing the buffer.
+  virtual void Read(Callback1<Buffer*>::Type* read_callback) = 0;
 
   // Given a class that supports the |Interface| and a related static method
   // interface_id(), which returns a const char*, this method returns true if
   // the class returns an interface pointer and assigns the pointer to
   // |interface_out|.  Otherwise this method returns false.
   template <class Interface>
   bool QueryInterface(scoped_refptr<Interface>* interface_out) {
     void* i = QueryInterface(Interface::interface_id());
     *interface_out = reinterpret_cast<Interface*>(i);
     return (NULL != i);
@@ skipping 83 matching lines @@
   // Initializes this filter, returns true if successful, false otherwise.
   virtual bool Initialize(AudioDecoder* decoder) = 0;
 
   // Sets the output volume.
   virtual void SetVolume(float volume) = 0;
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_FILTERS_H_