Implement WebGL's commit on the main thread

content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.cc

+// 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.
+
+#include "content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h"
+
+#include "cc/surfaces/surface.h"
+#include "cc/surfaces/surface_manager.h"
+#include "content/browser/compositor/surface_utils.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+
+namespace content {
+
+OffscreenCanvasCompositorFrameSink::OffscreenCanvasCompositorFrameSink(
+    const cc::SurfaceId& surface_id,
+    cc::mojom::MojoCompositorFrameSinkClientPtr client)
+    : surface_id_(surface_id), client_(std::move(client)) {}
+
+OffscreenCanvasCompositorFrameSink::~OffscreenCanvasCompositorFrameSink() {
+  if (surface_factory_) {
+    if (!GetSurfaceManager()) {

[piman, 2016/09/19 20:27:07]

nit: lookup the surface manager only once

cc::SurfaceManager* manager = GetSurfaceManager();
if (!manager) {
  [...]
} else {
  manager->InvalidateSurfaceClientId(...);
}

[xidachen, 2016/09/20 00:58:24]

Done.

+      // Inform SurfaceFactory that SurfaceManager's no longer alive to
+      // avoid its destruction error.
+      surface_factory_->DidDestroySurfaceManager();
+    } else {
+      GetSurfaceManager()->InvalidateSurfaceClientId(surface_id_.client_id());
+    }
+    surface_factory_->Destroy(surface_id_);
+  }
+}
+
+// static
+void OffscreenCanvasCompositorFrameSink::Create(
+    const cc::SurfaceId& surface_id,
+    cc::mojom::MojoCompositorFrameSinkClientPtr client,
+    cc::mojom::MojoCompositorFrameSinkRequest request) {
+  mojo::MakeStrongBinding(base::MakeUnique<OffscreenCanvasCompositorFrameSink>(
+                              surface_id, std::move(client)),
+                          std::move(request));
+}
+
+void OffscreenCanvasCompositorFrameSink::SubmitCompositorFrame(
+    cc::CompositorFrame frame,
+    const SubmitCompositorFrameCallback& callback) {
+  if (!surface_factory_) {
+    cc::SurfaceManager* manager = GetSurfaceManager();
+    surface_factory_ = base::MakeUnique<cc::SurfaceFactory>(manager, this);
+    surface_factory_->Create(surface_id_);
+
+    GetSurfaceManager()->RegisterSurfaceClientId(surface_id_.client_id());

[piman, 2016/09/19 20:27:07]

nit: manager-> instead of GetSurfaceManager()->

[xidachen, 2016/09/20 00:58:25]

Done.

+  }
+  surface_factory_->SubmitCompositorFrame(surface_id_, std::move(frame),
+                                          callback);
+}
+
+void OffscreenCanvasCompositorFrameSink::SetNeedsBeginFrame(
+    bool needs_begin_frame) {
+  NOTIMPLEMENTED();
+}
+
+void OffscreenCanvasCompositorFrameSink::ReturnResources(
+    const cc::ReturnedResourceArray& resources) {
+  client_->ReturnResources(resources);
+}
+
+void OffscreenCanvasCompositorFrameSink::WillDrawSurface(
+    const cc::SurfaceId& id,
+    const gfx::Rect& damage_rect) {}
+
+void OffscreenCanvasCompositorFrameSink::SetBeginFrameSource(
+    cc::BeginFrameSource* begin_frame_source) {}
+
+}  // namespace content