android: Use UIResource for overscroll glow

ui/base/android/system_ui_resource_manager.h

+// Copyright 2014 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 UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_
+#define UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_
+
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/observer_list.h"
+#include "cc/resources/ui_resource_client.h"
+#include "ui/base/android/system_ui_resource.h"
+#include "ui/base/ui_base_export.h"
+
+namespace cc {
+class UIResourceBitmap;
+}
+
+namespace ui {
+
+class SystemUIResourceLayer;
+class UIResourceProvider;
+
+class UI_BASE_EXPORT SystemUIResourceManager {
+ public:
+  SystemUIResourceManager();
+
+  void SetUIResourceProvider(ui::UIResourceProvider* provider) {

[jdduke (slow), 2014/07/12 01:01:09]

Could we instead make this an argument to the constructor so there's no
confusion about lifetimes?

[powei, 2014/07/16 17:10:52]

Done.  SystemUIResource is now owned by UIResourceProviderImpl

+    ui_resource_provider_ = provider;
+  }
+
+  void Subscribe(SystemUIResource::Type type, SystemUIResourceLayer* layer);
+  void Unsubscribe(SystemUIResource::Type type, SystemUIResourceLayer* layer);
+  void RefreshResourceOnSubscribers(SystemUIResource::Type type);
+  virtual ~SystemUIResourceManager() {}

[jdduke (slow), 2014/07/12 01:01:09]

Nit: Let's move the destructor up below the constructor.

[powei, 2014/07/16 17:10:52]

Done.

+
+ protected:
+  virtual void BuildResource(ui::SystemUIResource::Type type) = 0;

[jdduke (slow), 2014/07/12 01:01:09]

Can you explain why this class needs to be abstract?

[powei, 2014/07/16 17:10:52]

Acknowledged.

+
+  class Data : public SystemUIResourceClient {
+   public:
+    Data();
+    virtual ~Data();
+    void Subscribe(SystemUIResourceLayer* layer);
+    void Unsubscribe(SystemUIResourceLayer* layer);
+    void SetResource(scoped_ptr<SystemUIResource> resource);
+    void RefreshResource();
+    bool HasResource() { return resource_; }
+
+    // Implements SystemUIResourceClient.
+    virtual void OnUIResourceIdChanged() OVERRIDE;
+
+   private:
+    typedef ObserverList<SystemUIResourceLayer> Subscribers;
+
+    scoped_ptr<SystemUIResource> resource_;
+    Subscribers subscribers_;
+
+    DISALLOW_COPY_AND_ASSIGN(Data);
+  };
+
+  Data* GetData(SystemUIResource::Type type);
+
+  UIResourceProvider* GetUIResourceProvider();
+
+ private:
+  typedef base::ScopedPtrHashMap<int, Data> SystemUIResourceMap;
+  SystemUIResourceMap resource_map_;
+  UIResourceProvider* ui_resource_provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemUIResourceManager);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_