Add initial Viz implementation for OSR (see issue #2575).

The old shared surface implementation has been removed and will need to be
re-implemented using the Viz code path.

libcef/browser/osr/video_consumer_osr.h

@@ -0,0 +1,36 @@
+#ifndef LIBCEF_BROWSER_OSR_VIDEO_CONSUMER_OSR_H_
+#define LIBCEF_BROWSER_OSR_VIDEO_CONSUMER_OSR_H_
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "components/viz/host/client_frame_sink_video_capturer.h"
+
+class CefRenderWidgetHostViewOSR;
+
+class CefVideoConsumerOSR : public viz::mojom::FrameSinkVideoConsumer {
+ public:
+  explicit CefVideoConsumerOSR(CefRenderWidgetHostViewOSR* view);
+  ~CefVideoConsumerOSR() override;
+
+  void SetActive(bool active);
+  void SetFrameRate(base::TimeDelta frame_rate);
+  void SizeChanged();
+
+ private:
+  // viz::mojom::FrameSinkVideoConsumer implementation.
+  void OnFrameCaptured(
+      base::ReadOnlySharedMemoryRegion data,
+      ::media::mojom::VideoFrameInfoPtr info,
+      const gfx::Rect& content_rect,
+      viz::mojom::FrameSinkVideoConsumerFrameCallbacksPtr callbacks) override;
+  void OnStopped() override;
+
+  CefRenderWidgetHostViewOSR* const view_;
+  std::unique_ptr<viz::ClientFrameSinkVideoCapturer> video_capturer_;
+
+  base::WeakPtrFactory<CefVideoConsumerOSR> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CefVideoConsumerOSR);
+};
+
+#endif  // LIBCEF_BROWSER_OSR_VIDEO_CONSUMER_OSR_H_