media: add kMetadataBufferTypeGraphicBuffer

     */

    kMetadataBufferTypeGrallocSource = 1,

    /*

     * kMetadataBufferTypeGraphicBuffer is used to indicate that

     * the payload of the metadata buffers can be interpreted as

     * a GraphicBuffer.  It is only to be used by software encoders.

     * In this case, the metadata that the encoder receives

     * will have a byte stream that consists of two parts:

     * 1. First, there is an integer indicating that the metadata

     * contains a GraphicBuffer (kMetadataBufferTypeGraphicBuffer)

     * 2. This is followed by the pointer to the GraphicBuffer that

     * is to be encoded.  Encoder must not create a sp<> from this

     * graphic buffer, or free it, as it does not actually own this

     * buffer.

     * --------------------------------------------------------------

     * |  kMetadataBufferTypeGraphicBuffer | sizeof(GraphicBuffer *) |

     * --------------------------------------------------------------

     */

    kMetadataBufferTypeGraphicBuffer = 2,

    // Add more here...

} MetadataBufferType;