Convert offscreen canvas to use FrameSinkManagerHost.

third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom

Index: third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom
diff --git a/third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom b/third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom
index 3c32a12e060ce0c57cbe13ae08b98980a006a61b..16faf3a8465a42f61f4a90cb5c5a1fcd27d0638e 100644
--- a/third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom
+++ b/third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom
@@ -16,17 +16,20 @@ interface OffscreenCanvasSurface {
   Satisfy(cc.mojom.SurfaceSequence sequence);
 };
 
-interface OffscreenCanvasSurfaceFactory {
+// Creates OffscreenCanvasSurface and MojoCompositorFrameSink instances for use
+// with offscreen canvas.
+interface OffscreenCanvasProvider {
+  // TODO(kylechar): Observer interface shouldn't be DisplayCompositorClient.
+  // Create an OffscreenCanvasSurface for |frame_sink_id|. |client| will observe
+  // any changes to the SurfaceId associated with |frame_sink_id|.
   CreateOffscreenCanvasSurface(cc.mojom.FrameSinkId parent_frame_sink_id,
                                cc.mojom.FrameSinkId frame_sink_id,
                                cc.mojom.DisplayCompositorClient client,
-                               OffscreenCanvasSurface& service);
-};
+                               OffscreenCanvasSurface& surface);
 
-interface OffscreenCanvasCompositorFrameSinkProvider {
-  // TODO(fsamuel, xlai): Replace this with DisplayCompositor
+  // Create an MojoCompositorFrameSink for |frame_sink_id|. This must happen
+  // after creating an OffsreenCanvasSurface for |frame_sink_id|.
   CreateCompositorFrameSink(cc.mojom.FrameSinkId frame_sink_id,
                             cc.mojom.MojoCompositorFrameSinkClient client,
                             cc.mojom.MojoCompositorFrameSink& sink);
-};
-
+};