Add set_timestamp to cma's DecoderBufferBase

chromecast/media/cma/base/decoder_buffer_base.h

 // Copyright 2014 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 CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 #define CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_
 
 #include "base/basictypes.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 15 matching lines @@
  public:
   DecoderBufferBase();
 
   // Returns the stream id of this decoder buffer belonging to. it's optional
   // and default value is kPrimary.
   virtual StreamId stream_id() const = 0;
 
   // Returns the PTS of the frame.
   virtual base::TimeDelta timestamp() const = 0;
 
+  // Sets the PTS of the frame.
+  virtual void set_timestamp(const base::TimeDelta& timestamp) = 0;

[gunsch, 2015/06/05 20:02:48]

Today, DecoderBufferBase is immutable, which is a pretty nice property. We can
pass every single DecoderBufferBase around as const.

What about making something like a builder that makes a copy of a
DecoderBufferBase with a new timestamp, or perhaps a subclass
(TimeShiftedDecoderBufferBase) that takes a DecoderBufferBase and a new
timestamp in its constructor?

[halliwell, 2015/06/05 20:16:47]

Hmmm ... I could definitely do either of those if we want these to be immutable,
although:
* Although it's all 'const', it's not exactly immutable (see writable_data!)
* I don't believe we pass them around as const.  They seem to be passed as const
scoped_refptr<_>& a lot, which is fine to call non-const members on the enclosed
pointer.

Let me know what you think :)

+
   // Gets the frame data.
   virtual const uint8* data() const = 0;
   virtual uint8* writable_data() const = 0;
 
   // Returns the size of the frame in bytes.
   virtual size_t data_size() const = 0;
 
   // Returns the decrypt configuration.
   // Returns NULL if the buffer has no decrypt info.
   virtual const ::media::DecryptConfig* decrypt_config() const = 0;
 
   // Indicate if this is a special frame that indicates the end of the stream.
   // If true, functions to access the frame content cannot be called.
   virtual bool end_of_stream() const = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<DecoderBufferBase>;
   virtual ~DecoderBufferBase();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DecoderBufferBase);
 };
 
 }  // namespace media
 }  // namespace chromecast
 
 #endif  // CHROMECAST_MEDIA_CMA_BASE_DECODER_BUFFER_BASE_H_