Proxy RtcVideoDecoder calls to a media::VideoDecoder.

content/renderer/media/gpu/rtc_video_decoder_factory.h

 // Copyright 2013 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 CONTENT_RENDERER_MEDIA_GPU_RTC_VIDEO_DECODER_FACTORY_H_
 #define CONTENT_RENDERER_MEDIA_GPU_RTC_VIDEO_DECODER_FACTORY_H_
 
+#include "base/callback.h"
 #include "base/macros.h"
-#include "base/threading/thread.h"
+#include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "third_party/webrtc/media/engine/webrtcvideodecoderfactory.h"
 #include "third_party/webrtc/modules/video_coding/include/video_codec_interface.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace media {
+class VideoDecoder;
+}  // namespace media
+
 namespace webrtc {
 class VideoDecoder;
 }  // namespace webrtc
 
-namespace media {
-class GpuVideoAcceleratorFactories;
-}  // namespace media
-
 namespace content {
 
 // TODO(wuchengli): add unittest.
 class CONTENT_EXPORT RTCVideoDecoderFactory
     : NON_EXPORTED_BASE(public cricket::WebRtcVideoDecoderFactory) {
  public:
-  explicit RTCVideoDecoderFactory(
-      media::GpuVideoAcceleratorFactories* gpu_factories);
+  // A factory closure which can be run to create a media::VideoDecoder.
+  using CreateVideoDecoderCB =
+      base::Callback<std::unique_ptr<media::VideoDecoder>()>;
+
+  // |create_video_decoder_cb| will be passed to the created RtcVideoDecoder,
+  // which will run it on |decoder_task_runner|'s thread. All calls made on
+  // RtcVideoDecoder will be proxied on this thread to the media::VideoDecoder
+  // returned by this callback. For more information, see RtcVideoDeocder.
+  RTCVideoDecoderFactory(
+      const CreateVideoDecoderCB& create_video_decoder_cb,

[emircan, 2016/10/20 17:52:25]

Can we name this as create_mojo_video_decoder_cb or
create_video_decoder_client_cb? Currently it sounds like the callback to create
the actual decoder implementation in gpu process here:
https://cs.chromium.org/chromium/src/media/gpu/gpu_video_decode_accelerator_f...

[slan, 2016/10/25 21:25:32]

Using "mojo" in the name would be inaccurate right now, and using "client" would
be misleading (I think "Client" tends to have different implications in Chrome).
What about create_media_video_decoder_cb? I could also beef up the comments
above the type alias.

+      const scoped_refptr<base::SingleThreadTaskRunner>& decoder_task_runner);
   ~RTCVideoDecoderFactory() override;
 
   // Runs on Chrome_libJingle_WorkerThread. The child thread is blocked while
   // this runs.
   webrtc::VideoDecoder* CreateVideoDecoder(
       webrtc::VideoCodecType type) override;
 
   // Runs on Chrome_libJingle_WorkerThread. The child thread is blocked while
   // this runs.
   void DestroyVideoDecoder(webrtc::VideoDecoder* decoder) override;
 
  private:
-  media::GpuVideoAcceleratorFactories* gpu_factories_;
+  // These are cached and passed into RtcVideoDecoder::Create().
+  const CreateVideoDecoderCB create_video_decoder_cb_;
+  const scoped_refptr<base::SingleThreadTaskRunner> decoder_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCVideoDecoderFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_GPU_RTC_VIDEO_DECODER_FACTORY_H_