Add the base class for decoder buffers used in cast media.

chromecast/media/cma/base/decoder_buffer_base.h

Index: chromecast/media/cma/base/decoder_buffer_base.h
diff --git a/chromecast/media/cma/base/decoder_buffer_base.h b/chromecast/media/cma/base/decoder_buffer_base.h
new file mode 100644
index 0000000000000000000000000000000000000000..9143104f14a8aefe979d0c57d26c668562478e68
--- /dev/null
+++ b/chromecast/media/cma/base/decoder_buffer_base.h
@@ -0,0 +1,57 @@
+// 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"
+#include "base/time/time.h"
+
+namespace media {
+class DecryptConfig;
+}
+
+namespace chromecast {
+namespace media {
+
+// DecoderBufferBase exposes only the properties of an audio/video buffer.
+// The way a DecoderBufferBase is created and organized in memory
+// is left as a detail of the implementation of derived classes.
+class DecoderBufferBase
+    : public base::RefCountedThreadSafe<DecoderBufferBase> {
+ public:
+  DecoderBufferBase();
+
+  // Returns the PTS of the frame.
+  virtual base::TimeDelta timestamp() const = 0;
+
+  // 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 int 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_