aw: Share cc::Display instance

android_webview/browser/surfaces_instance.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 ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_
+#define ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_
+
+#include <memory>
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "cc/surfaces/display_client.h"
+#include "cc/surfaces/surface_factory_client.h"
+#include "cc/surfaces/surface_id.h"
+
+namespace cc {
+class Display;
+class SurfaceIdAllocator;
+class SurfaceFactory;
+class SurfaceManager;
+}
+
+namespace gfx {
+class Rect;
+class Size;
+class Transform;
+}
+
+namespace android_webview {
+
+class AwGLSurface;
+class ParentOutputSurface;
+class ScopedAppGLStateRestore;
+
+class SurfacesInstance : public base::RefCounted<SurfacesInstance>,
+                         public cc::DisplayClient,
+                         public cc::SurfaceFactoryClient {
+ public:
+  static scoped_refptr<SurfacesInstance> GetOrCreateInstance();
+
+  std::unique_ptr<cc::SurfaceIdAllocator> CreateSurfaceIdAllocator();
+  cc::SurfaceManager* GetSurfaceManager();
+  void SetBackingFrameBufferObject(int framebuffer_binding_ext);
+
+  void DrawAndSwap(const gfx::Size& viewport,
+                   const gfx::Rect& clip,
+                   const gfx::Transform& transform,
+                   const gfx::Size& frame_size,
+                   const cc::SurfaceId& child_id,
+                   const ScopedAppGLStateRestore& gl_state);
+
+  void AddChildId(const cc::SurfaceId& child_id);
+  void RemoveChildId(const cc::SurfaceId& child_id);
+
+ private:
+  friend class base::RefCounted<SurfacesInstance>;
+
+  SurfacesInstance();
+  ~SurfacesInstance() override;
+
+  // cc::DisplayClient overrides.
+  void DisplayOutputSurfaceLost() override {}
+  void DisplaySetMemoryPolicy(const cc::ManagedMemoryPolicy& policy) override {}
+
+  // cc::SurfaceFactoryClient implementation.
+  void ReturnResources(const cc::ReturnedResourceArray& resources) override;
+  void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
+
+  void SetEmptyRootFrame();
+
+  uint32_t next_surface_id_namespace_;
+
+  scoped_refptr<AwGLSurface> gl_surface_;

[hush (inactive), 2016/06/29 00:03:12]

why is this scoped_refptr while others are unique_ptrs? It is not shared by
anybody else and it's completely own by this class.
Can this be unique_ptr as well?

[boliu, 2016/06/29 01:01:04]

GLSurface is refcounted. Can't mix refcounted and unique_ptr.

It is also held by the InProcessCommandBuffer for example, so it's not like this
is the only reference to it.

+  std::unique_ptr<cc::SurfaceManager> surface_manager_;
+  std::unique_ptr<cc::Display> display_;
+  std::unique_ptr<cc::SurfaceIdAllocator> surface_id_allocator_;
+  std::unique_ptr<cc::SurfaceFactory> surface_factory_;
+
+  cc::SurfaceId root_id_;
+  std::vector<cc::SurfaceId> child_ids_;
+
+  // This is owned by |display_|.
+  ParentOutputSurface* output_surface_;
+
+  DISALLOW_COPY_AND_ASSIGN(SurfacesInstance);
+};
+
+}  // namespace android_webview
+
+#endif  // ANDROID_WEBVIEW_BROWSER_SURFACES_INSTANCE_H_