[PPAPI] Implement media stream video track API

content/renderer/pepper/pepper_media_stream_video_track_host.h

+// Copyright (c) 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 CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_VIDEO_TRACK_HOST_H_
+#define CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_VIDEO_TRACK_HOST_H_
+
+#include "base/compiler_specific.h"
+#include "content/public/renderer/media_stream_video_sink.h"
+#include "content/renderer/pepper/pepper_media_stream_track_host_base.h"
+#include "media/base/video_frame.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
+#include "ui/gfx/size.h"
+
+namespace content {
+
+class PepperMediaStreamVideoTrackHost :
+  public PepperMediaStreamTrackHostBase,
+  public MediaStreamVideoSink {
+ public:
+  PepperMediaStreamVideoTrackHost(RendererPpapiHost* host,
+                                  PP_Instance instance,
+                                  PP_Resource resource,
+                                  const blink::WebMediaStreamTrack& track);
+
+  virtual ~PepperMediaStreamVideoTrackHost();
+
+  // PepperMediaStreamTrackHostBase overrides:
+  virtual void OnClose() OVERRIDE;
+
+  // MediaStreamVideoSink overrides:
+  virtual void OnVideoFrame(
+      const scoped_refptr<media::VideoFrame>& frame) OVERRIDE;
+
+ protected:
+  virtual void DidConnectPendingHostToResource() OVERRIDE;

[dmichael (off chromium), 2014/01/09 21:06:47]

nit: I think all the virtual functions could be private.

[Peng, 2014/01/10 19:14:30]

Done.

+
+ private:
+  blink::WebMediaStreamTrack track_;
+
+  // True if it has been added to |blink::WebMediaStreamTrack| as a sink.
+  bool connected_;
+
+  // Frame size in pixels.
+  gfx::Size frame_size_;

[dmichael (off chromium), 2014/01/09 21:06:47]

I found this name slightly confusing. It might be nice for the name to make the
units clear and make it clear that it doesn't include the header size. So
maybe...
num_pixels_per_frame_
?

[Peng, 2014/01/10 19:14:30]

No. It is a gfx::Size. I mean the width and height are in pixels.

[dmichael (off chromium), 2014/01/13 21:26:47]

Okay, sorry for my misunderstanding. I think the previous comment was better, or
no comment at all. The current comment just rephrases the variable name.

+
+  // Frame format.
+  media::VideoFrame::Format frame_format_;
+
+  // The size of frame pixels in bytes.
+  uint32_t frame_data_size_;
+
+  DISALLOW_COPY_AND_ASSIGN(PepperMediaStreamVideoTrackHost);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_PEPPER_PEPPER_MEDIA_STREAM_VIDEO_TRACK_HOST_H_