Create manager to track OffscreenCanvasSurfaceImpl instances

content/browser/renderer_host/offscreen_canvas_surface_manager.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_MANAGER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_SURFACE_MANAGER_H_
+
+#include "base/containers/hash_tables.h"
+#include "base/memory/weak_ptr.h"
+#include "cc/surfaces/surface_id.h"
+#include "content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h"
+#include "content/browser/renderer_host/offscreen_canvas_surface_impl.h"
+
+namespace content {
+
+class CONTENT_EXPORT OffscreenCanvasSurfaceManager {
+ public:
+  OffscreenCanvasSurfaceManager();
+  ~OffscreenCanvasSurfaceManager();
+
+  static OffscreenCanvasSurfaceManager* GetInstance();
+
+  void RegisterOffscreenCanvasSurfaceInstance(cc::FrameSinkId,
+                                              OffscreenCanvasSurfaceImpl*);
+  void UnregisterOffscreenCanvasSurfaceInstance(cc::FrameSinkId);
+
+  void RegisterCompositorFrameSinkInstance(cc::FrameSinkId,
+                                           OffscreenCanvasCompositorFrameSink*);
+  void UnregisterCompositorFrameSinkInstance(cc::FrameSinkId);
+
+  OffscreenCanvasSurfaceImpl* GetSurfaceInstance(cc::FrameSinkId);
+  OffscreenCanvasCompositorFrameSink* GetCompositorFrameSinkInstance(
+      cc::FrameSinkId);
+
+ private:
+  friend class OffscreenCanvasSurfaceManagerTest;
+
+  std::unordered_map<cc::FrameSinkId,

[xlai (Olivia), 2016/11/11 22:56:57]

I'm using a FrameSinkId to identify the instance, in response to fsamuel@'s
comment.

+                     base::WeakPtr<OffscreenCanvasSurfaceImpl>,
+                     cc::FrameSinkIdHash>
+      registered_surface_instances_;
+  std::unordered_map<cc::FrameSinkId,
+                     base::WeakPtr<OffscreenCanvasCompositorFrameSink>,
+                     cc::FrameSinkIdHash>
+      registered_compositor_frame_sink_instances_;
+  DISALLOW_COPY_AND_ASSIGN(OffscreenCanvasSurfaceManager);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_OFFSCREEN_CANVAS_SURFACE_MANAGER_H_