media: Add MojoDecoderBuffer{Reader|Writer}

media/mojo/services/mojo_decryptor_service.h

Index: media/mojo/services/mojo_decryptor_service.h
diff --git a/media/mojo/services/mojo_decryptor_service.h b/media/mojo/services/mojo_decryptor_service.h
index 58dc7bc4af3f3d2de0bde47321ca62e917195494..bb68f61f154c5cae993da1ea9be1328fbb0000b1 100644
--- a/media/mojo/services/mojo_decryptor_service.h
+++ b/media/mojo/services/mojo_decryptor_service.h
@@ -17,12 +17,13 @@
 #include "media/base/decryptor.h"
 #include "media/mojo/interfaces/decryptor.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
-#include "mojo/public/cpp/system/data_pipe.h"
 
 namespace media {
 
 class DecoderBuffer;
 class MediaKeys;
+class MojoDecoderBufferReader;
+class MojoDecoderBufferWriter;
 
 // A mojom::Decryptor implementation. This object is owned by the creator,
 // and uses a weak binding across the mojo interface.
@@ -81,18 +82,14 @@ class MojoDecryptorService : public mojom::Decryptor {
                       media::Decryptor::Status status,
                       const scoped_refptr<VideoFrame>& frame);
 
-  // Helper functions to write and read a DecoderBuffer.
-  mojom::DecoderBufferPtr TransferDecoderBuffer(
-      const scoped_refptr<DecoderBuffer>& buffer);
-  scoped_refptr<DecoderBuffer> ReadDecoderBuffer(
-      mojom::DecoderBufferPtr buffer);
-
   // A weak binding is used to connect to the MojoDecryptor.
   mojo::Binding<mojom::Decryptor> binding_;
 
-  // DataPipes for serializing the data section of DecoderBuffer into/from.
-  mojo::ScopedDataPipeProducerHandle producer_handle_;
-  mojo::ScopedDataPipeConsumerHandle consumer_handle_;
+  // Helper class to send decrypted DecoderBuffer to the client.
+  std::unique_ptr<MojoDecoderBufferWriter> mojo_decoder_buffer_writer_;
+
+  // Helper class to receive encrypted DecoderBuffer from the client.
+  std::unique_ptr<MojoDecoderBufferReader> mojo_decoder_buffer_reader_;
 
   // Keep ownership of |cdm_| while it is being used. |decryptor_| is the actual
   // Decryptor referenced by |cdm_|.