Reland "Update mojo Decryptor interface to support reusing shared memory"

media/mojo/services/mojo_decryptor.h

 // Copyright 2015 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 MEDIA_MOJO_SERVICES_MOJO_DECRYPTOR_H_
 #define MEDIA_MOJO_SERVICES_MOJO_DECRYPTOR_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
@@ skipping 39 matching lines @@
   void OnBufferDecrypted(const DecryptCB& decrypt_cb,
                          interfaces::Decryptor::Status status,
                          interfaces::DecoderBufferPtr buffer);
   void OnAudioDecoded(const AudioDecodeCB& audio_decode_cb,
                       interfaces::Decryptor::Status status,
                       mojo::Array<interfaces::AudioBufferPtr> audio_buffers);
   void OnVideoDecoded(const VideoDecodeCB& video_decode_cb,
                       interfaces::Decryptor::Status status,
                       interfaces::VideoFramePtr video_frame);
 
+  // Called when done with a VideoFrame in order to reuse the shared memory.
+  void ReleaseSharedBuffer(mojo::ScopedSharedBufferHandle buffer,
+                           size_t buffer_size);
+
   // To pass DecoderBuffers to and from the MojoDecryptorService, 2 data pipes
   // are required (one each way). At initialization both pipes are created,
   // and then the handles are passed to the MojoDecryptorService.
   void CreateDataPipes();
 
   // Helper functions to write and read a DecoderBuffer.
   interfaces::DecoderBufferPtr TransferDecoderBuffer(
       const scoped_refptr<DecoderBuffer>& buffer);
   scoped_refptr<DecoderBuffer> ReadDecoderBuffer(
       interfaces::DecoderBufferPtr buffer);
@@ skipping 10 matching lines @@
   NewKeyCB new_video_key_cb_;
 
   base::WeakPtrFactory<MojoDecryptor> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MojoDecryptor);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_MOJO_SERVICES_MOJO_DECRYPTOR_H_