Implement WebGL's commit on the main thread

content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.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 CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_COMPOSITOR_FRAME_SINK_H_
+#define CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_COMPOSITOR_FRAME_SINK_H_
+
+#include "cc/surfaces/surface_factory.h"
+#include "cc/surfaces/surface_factory_client.h"
+#include "third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom.h"
+
+namespace content {
+
+class OffscreenCanvasCompositorFrameSink
+    : public cc::mojom::MojoCompositorFrameSink,
+      public cc::SurfaceFactoryClient {
+ public:
+  OffscreenCanvasCompositorFrameSink(
+      const cc::SurfaceId& surface_id,
+      cc::mojom::MojoCompositorFrameSinkClientPtr client);
+  ~OffscreenCanvasCompositorFrameSink() override;
+
+  static void Create(const cc::SurfaceId& surface_id,
+                     cc::mojom::MojoCompositorFrameSinkClientPtr client,
+                     cc::mojom::MojoCompositorFrameSinkRequest request);
+
+  void SubmitCompositorFrame(

[danakj, 2016/09/19 20:29:25]

Put a comment above these that say what interface/class they are implementing.

+      cc::CompositorFrame frame,
+      const SubmitCompositorFrameCallback& callback) override;
+  void SetNeedsBeginFrame(bool needs_begin_frame) override;
+
+  // cc::SurfaceFactoryClient implementation.
+  void ReturnResources(const cc::ReturnedResourceArray& resources) override;
+  void WillDrawSurface(const cc::SurfaceId& id,
+                       const gfx::Rect& damage_rect) override;
+  void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
+
+ private:
+  cc::SurfaceId surface_id_;
+  std::unique_ptr<cc::SurfaceFactory> surface_factory_;
+  cc::mojom::MojoCompositorFrameSinkClientPtr client_;
+
+  DISALLOW_COPY_AND_ASSIGN(OffscreenCanvasCompositorFrameSink);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_COMPOSITOR_FRAME_SINK_H_