Add a stub implementation for Mojo AudioDecoder interface

This CL adds a stub service that implements interface::AudioDecoder.
The interface is modified to pass the AudioDecoderClient which
can transfer the results back to the proxy.

BUG=542910

Review URL: https://codereview.chromium.org/1808593002

Cr-Commit-Position: refs/heads/master@{#381574}

media/mojo/interfaces/audio_decoder.mojom

@@ -18,7 +18,7 @@ interface AudioDecoder {
   // For the unencrypted streams the |cdm_id| is ignored. Executed the callback
   // with whether the initialization succeeded, and whether the pipeline needs
   // bitstream conversion.
-  Initialize(AudioDecoderConfig config, int32 cdm_id)
+  Initialize(AudioDecoderClient client, AudioDecoderConfig config, int32 cdm_id)
      => (bool success, bool needs_bitstream_conversion);
 
   // Sends the |buffer| to the underlying codec. Should be called only after

media/mojo/services/BUILD.gn

@@ -124,6 +124,23 @@ source_set("cdm_service") {
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
+source_set("audio_decoder_service") {
+  sources = [
+    "mojo_audio_decoder_service.cc",
+    "mojo_audio_decoder_service.h",
+  ]
+
+  deps = [
+    ":cdm_service",
+    "//base",
+    "//media",
+    "//media:shared_memory_support",
+    "//media/mojo/common",
+    "//media/mojo/interfaces",
+    "//mojo/common",
+  ]
+}
+
 source_set("renderer_service") {
   sources = [
     "demuxer_stream_provider_shim.cc",
@@ -158,6 +175,7 @@ source_set("application") {
   public_configs = [ ":mojo_media_config" ]
 
   deps = [
+    ":audio_decoder_service",
     ":cdm_service",
     ":renderer_service",
     "//base",

media/mojo/services/mojo_audio_decoder_service.cc

+// Copyright 2016 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.
+
+#include "base/logging.h"
+#include "media/mojo/services/mojo_audio_decoder_service.h"
+
+namespace media {
+
+MojoAudioDecoderService::MojoAudioDecoderService(
+    scoped_ptr<AudioDecoder> decoder,
+    mojo::InterfaceRequest<interfaces::AudioDecoder> request)
+    : binding_(this, std::move(request)), decoder_(std::move(decoder)) {}
+
+MojoAudioDecoderService::~MojoAudioDecoderService() {}
+
+void MojoAudioDecoderService::Initialize(
+    interfaces::AudioDecoderClientPtr client,
+    interfaces::AudioDecoderConfigPtr config,
+    int32_t cdm_id,
+    const InitializeCallback& callback) {
+  NOTIMPLEMENTED();
+  callback.Run(false, false);
+}
+
+void MojoAudioDecoderService::Decode(interfaces::DecoderBufferPtr buffer,
+                                     const DecodeCallback& callback) {
+  NOTIMPLEMENTED();
+  callback.Run(DecodeStatus::DECODE_ERROR);
+}
+
+void MojoAudioDecoderService::Reset(const ResetCallback& callback) {
+  NOTIMPLEMENTED();
+  callback.Run();
+}
+
+}  // namespace media

media/mojo/services/mojo_audio_decoder_service.h

+// Copyright 2016 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_AUDIO_DECODER_SERVICE_H_
+#define MEDIA_MOJO_SERVICES_MOJO_AUDIO_DECODER_SERVICE_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "media/mojo/interfaces/audio_decoder.mojom.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace media {
+
+class MojoAudioDecoderService : public interfaces::AudioDecoder {
+ public:
+  MojoAudioDecoderService(
+      scoped_ptr<AudioDecoder> decoder,
+      mojo::InterfaceRequest<interfaces::AudioDecoder> request);
+
+  ~MojoAudioDecoderService() final;
+
+  // interfaces::AudioDecoder implementation
+  void Initialize(interfaces::AudioDecoderClientPtr client,
+                  interfaces::AudioDecoderConfigPtr config,
+                  int32_t cdm_id,
+                  const InitializeCallback& callback) final;
+
+  void Decode(interfaces::DecoderBufferPtr buffer,
+              const DecodeCallback& callback) final;
+
+  void Reset(const ResetCallback& callback) final;
+
+ private:
+  // A binding represents the association between the service and the
+  // communication channel, i.e. the pipe.
+  mojo::StrongBinding<interfaces::AudioDecoder> binding_;
+
+  // The AudioDecoder that does actual decoding work.
+  scoped_ptr<AudioDecoder> decoder_;
+
+  // The destination for the decoded buffers.
+  interfaces::AudioDecoderClientPtr client_;
+
+  DISALLOW_COPY_AND_ASSIGN(MojoAudioDecoderService);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_MOJO_SERVICES_MOJO_AUDIO_DECODER_SERVICE_H_