Establish mojo service between Canvas (blink) and SurfaceManager (browser)

content/browser/renderer_host/offscreen_canvas_surface_service_impl.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_SURFACE_SERVICE_IMPL_H_
+#define CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_SURFACE_SERVICE_IMPL_H_
+
+#include "cc/surfaces/surface_factory.h"
+#include "cc/surfaces/surface_factory_client.h"
+#include "cc/surfaces/surface_id.h"
+#include "cc/surfaces/surface_id_allocator.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/string.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface_service.mojom.h"
+
+namespace content {
+
+class OffscreenCanvasSurfaceServiceImpl
+    : public blink::mojom::OffscreenCanvasSurfaceService,
+      public cc::SurfaceFactoryClient {
+ public:
+  static void Create(mojo::InterfaceRequest<
+                     blink::mojom::OffscreenCanvasSurfaceService> request);
+  ~OffscreenCanvasSurfaceServiceImpl() override;

[dcheng, 2016/06/14 09:56:45]

You can make this private (StrongBinding will delete through the base-class
pointer)

[xlai (Olivia), 2016/06/14 21:10:17]

Done.

+
+  void GetSurfaceId(const GetSurfaceIdCallback& callback) override;

[dcheng, 2016/06/14 09:56:45]

Nit: comment on which thing this is overriding (like the comment on line 33)

[xlai (Olivia), 2016/06/14 21:10:17]

Done.

+  void RequestSurfaceCreation(const cc::SurfaceId& surface_id) override;
+  void Require(const cc::SurfaceId& surface_id,
+               const cc::SurfaceSequence& sequence) override;
+  void Satisfy(const cc::SurfaceSequence& sequence) override;
+
+  // cc::SurfaceFactoryClient implementation.
+  void ReturnResources(const cc::ReturnedResourceArray& resources) override;
+  void WillDrawSurface(cc::SurfaceId id, const gfx::Rect& damage_rect) override;

[dcheng, 2016/06/14 09:56:45]

It's not introduced by this CL, but how come we pass SurfaceId by value and
sometimes we pass by const ref?

[xlai (Olivia), 2016/06/14 21:10:17]

When I implement the functions in the next patch (Issue 619136), I'll see if I
can clean up this part on cc surfaceFactory API if it hasn't been done.

+  void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
+
+ private:
+  explicit OffscreenCanvasSurfaceServiceImpl(
+      mojo::InterfaceRequest<blink::mojom::OffscreenCanvasSurfaceService>
+          request);
+
+  // Surface-related state
+  std::unique_ptr<cc::SurfaceIdAllocator> id_allocator_;
+  std::unique_ptr<cc::SurfaceFactory> surface_factory_;
+
+  mojo::StrongBinding<blink::mojom::OffscreenCanvasSurfaceService> binding_;
+
+  DISALLOW_COPY_AND_ASSIGN(OffscreenCanvasSurfaceServiceImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_SURFACE_SERVICE_IMPL_H_