Create a single IPC call for OffscreenCanvasProvider

For BeginFrameProvider, we don't need the multi-call location.
Hence, we can remove one IPC call from the process.

Bug: 833902
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: Id360cd544cfdb6c583f408b083850b30990f4231
Reviewed-on: https://chromium-review.googlesource.com/1032798Reviewed-by: Justin Novosad <junov@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Olivia Lai <xlai@chromium.org>
Commit-Queue: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554829}

content/browser/renderer_host/offscreen_canvas_provider_impl.cc

@@ -66,6 +66,18 @@ void OffscreenCanvasProviderImpl::CreateCompositorFrameSink(
                                           std::move(request));
 }
 
+void OffscreenCanvasProviderImpl::CreateSimpleCompositorFrameSink(
+    const viz::FrameSinkId& parent_frame_sink_id,
+    const viz::FrameSinkId& frame_sink_id,
+    blink::mojom::OffscreenCanvasSurfaceClientPtr surface_client,
+    viz::mojom::CompositorFrameSinkClientPtr client,
+    viz::mojom::CompositorFrameSinkRequest request) {
+  CreateOffscreenCanvasSurface(parent_frame_sink_id, frame_sink_id,
+                               std::move(surface_client));
+  CreateCompositorFrameSink(frame_sink_id, std::move(client),
+                            std::move(request));
+}
+
 void OffscreenCanvasProviderImpl::DestroyOffscreenCanvasSurface(
     viz::FrameSinkId frame_sink_id) {
   canvas_map_.erase(frame_sink_id);

content/browser/renderer_host/offscreen_canvas_provider_impl.h

@@ -41,6 +41,12 @@ class CONTENT_EXPORT OffscreenCanvasProviderImpl
       const viz::FrameSinkId& frame_sink_id,
       viz::mojom::CompositorFrameSinkClientPtr client,
       viz::mojom::CompositorFrameSinkRequest request) override;
+  void CreateSimpleCompositorFrameSink(
+      const viz::FrameSinkId& parent_frame_sink_id,
+      const viz::FrameSinkId& frame_sink_id,
+      blink::mojom::OffscreenCanvasSurfaceClientPtr surface_client,
+      viz::mojom::CompositorFrameSinkClientPtr client,
+      viz::mojom::CompositorFrameSinkRequest request) override;
 
  private:
   friend class OffscreenCanvasProviderImplTest;

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

@@ -27,4 +27,12 @@ interface OffscreenCanvasProvider {
   CreateCompositorFrameSink(viz.mojom.FrameSinkId frame_sink_id,
                             viz.mojom.CompositorFrameSinkClient client,
                             viz.mojom.CompositorFrameSink& sink);
+
+  // Ceate CompositorFrameSink directly in a single call (instead of going
+  // through both function above).
+  CreateSimpleCompositorFrameSink(viz.mojom.FrameSinkId parent_frame_sink_id,
+                                  viz.mojom.FrameSinkId frame_sink_id,
+                                  OffscreenCanvasSurfaceClient surface_client,
+                                  viz.mojom.CompositorFrameSinkClient client,
+                                  viz.mojom.CompositorFrameSink& sink);
 };

third_party/blink/renderer/platform/graphics/begin_frame_provider.cc

@@ -37,15 +37,12 @@ void BeginFrameProvider::CreateCompositorFrameSink() {
   mojom::blink::OffscreenCanvasSurfaceClientPtr ocs_client;
   ocs_binding_.Bind(mojo::MakeRequest(&ocs_client), task_runner);
 
-  canvas_provider->CreateOffscreenCanvasSurface(
-      parent_frame_sink_id_, frame_sink_id_, std::move(ocs_client));
-
   viz::mojom::blink::CompositorFrameSinkClientPtr client;
   cfs_binding_.Bind(mojo::MakeRequest(&client), task_runner);
 
-  canvas_provider->CreateCompositorFrameSink(
-      frame_sink_id_, std::move(client),
-      mojo::MakeRequest(&compositor_frame_sink_));
+  canvas_provider->CreateSimpleCompositorFrameSink(
+      parent_frame_sink_id_, frame_sink_id_, std::move(ocs_client),
+      std::move(client), mojo::MakeRequest(&compositor_frame_sink_));
 }
 
 void BeginFrameProvider::RequestBeginFrame() {