media: scaffolding and plumbing for MojoRenderer{Impl, Service}

media/mojo/services/mojo_renderer_client_impl.h

+// 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 MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_
+#define MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_
+
+#include "base/macros.h"
+#include "media/base/renderer.h"
+#include "media/mojo/interfaces/media_renderer.mojom.h"
+#include "mojo/public/interfaces/application/service_provider.mojom.h"
+
+namespace media {
+
+// A media::Renderer that proxies to a mojo::MediaRenderer.
+class MojoRendererClientImpl : public Renderer,

[xhwang, 2014/09/02 17:05:52]

From media pipeline's perspective, this is a mojo based Renderer implementation.
The fact that it's also a mojo::MediaRendererClient (hence the "Client") is an
implementation detail. How about s/MojoRendererClientImpl/MojoRendererImpl?

[tim (not reviewing), 2014/09/02 18:20:05]

Yeah, I had it named that way before... I think the reason I changed it is
because the "mojo based renderer implementation" is actually two-fold: it has a
client and a service.  Although I didn't make this really obvious as the two
names aren't symmetric.  What about if we had 

MojoRendererClientImpl / MojoRendererServiceImpl
or
MojoRendererImplClient / MojoRendererImplService

?

+                               public mojo::MediaRendererClient {
+ public:
+  // |media_renderer_provider| is the ServiceProvider for an Application
+  // that is hosting a mojo::MediaRenderer.
+  explicit MojoRendererClientImpl(
+      mojo::ServiceProvider* media_renderer_provider);

[xhwang, 2014/09/02 17:05:53]

This can also take a DemuxerStreamProvider* demuxer_stream_provider in the
future.

See https://codereview.chromium.org/523283002/

[tim (not reviewing), 2014/09/02 18:20:05]

cool!

+  virtual ~MojoRendererClientImpl();
+
+  // Renderer implementation.
+  virtual void Initialize(const PipelineStatusCB& init_cb,
+                          const StatisticsCB& statistics_cb,
+                          const base::Closure& ended_cb,
+                          const PipelineStatusCB& error_cb,
+                          const BufferingStateCB& buffering_state_cb,
+                          const TimeDeltaCB& get_duration_cb) OVERRIDE;
+  virtual void Flush(const base::Closure& flush_cb) OVERRIDE;
+  virtual void StartPlayingFrom(base::TimeDelta time) OVERRIDE;
+  virtual void SetPlaybackRate(float playback_rate) OVERRIDE;
+  virtual void SetVolume(float volume) OVERRIDE;
+  virtual base::TimeDelta GetMediaTime() OVERRIDE;
+  virtual bool HasAudio() OVERRIDE;
+  virtual bool HasVideo() OVERRIDE;
+  virtual void SetCdm(MediaKeys* cdm) OVERRIDE;
+
+  // mojo::MediaRendererClient implementation.
+  virtual void OnTimeUpdate(int64_t time_delta_usec) MOJO_OVERRIDE;
+  virtual void OnBufferingStateChange(
+      mojo::BufferingState state) MOJO_OVERRIDE;
+  virtual void OnEnded() MOJO_OVERRIDE;
+  virtual void OnError() MOJO_OVERRIDE;
+
+ private:
+  mojo::MediaRendererPtr remote_renderer_;
+  DISALLOW_COPY_AND_ASSIGN(MojoRendererClientImpl);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_MOJO_SERVICES_MOJO_RENDERER_IMPL_H_