[Android] Add a native pull-to-refresh overscroll effect

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 "cc/resources/ui_resource_client.h"
+#include "ui/base/android/system_ui_resource_type.h"
 #include "ui/base/ui_base_export.h"
 
 namespace ui {
 
 // Interface for loading and accessing shared system UI resources.
 class UI_BASE_EXPORT SystemUIResourceManager {
  public:
-  enum ResourceType {
-    OVERSCROLL_EDGE = 0,
-    OVERSCROLL_GLOW,
-    OVERSCROLL_GLOW_L,
-    RESOURCE_TYPE_FIRST = OVERSCROLL_EDGE,
-    RESOURCE_TYPE_LAST = OVERSCROLL_GLOW_L
-  };
-
   virtual ~SystemUIResourceManager() {}
 
   // Optionally trigger bitmap loading for a given |resource|, if necessary.
   // Note that this operation may be asynchronous, and subsequent queries to
   // |GetUIResourceId()| will yield a valid result only after loading finishes.
   // This method is particularly useful for idly loading a resource before an
   // explicit cc::UIResourceId is required. Repeated calls will be ignored.
-  virtual void PreloadResource(ResourceType resource) = 0;
+  virtual void PreloadResource(SystemUIResourceType resource) = 0;
 
   // Return the resource id associated with |resource|. If loading hasn't yet
   // begun for the given |resource|, it will be triggered immediately. If
   // loading is asynchronous, 0 will be returned until loading has finished, and
   // the caller is responsible for re-querying until a valid id is returned.
-  virtual cc::UIResourceId GetUIResourceId(ResourceType resource) = 0;
+  virtual cc::UIResourceId GetUIResourceId(SystemUIResourceType resource) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_ANDROID_SYSTEM_UI_RESOURCE_MANAGER_H_