android: Use UIResource for overscroll glow

content/browser/android/edge_effect.h

Index: content/browser/android/edge_effect.h
diff --git a/content/browser/android/edge_effect.h b/content/browser/android/edge_effect.h
index b8febba22d2a77673be3198c46b4e6d26cc39c21..62498e095ed22903f9a6488fb13849f6eb09309a 100644
--- a/content/browser/android/edge_effect.h
+++ b/content/browser/android/edge_effect.h
@@ -6,7 +6,7 @@
 #define CONTENT_BROWSER_ANDROID_EDGE_EFFECT_H_
 
 #include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "ui/gfx/size_f.h"
 
@@ -24,7 +24,14 @@ namespace content {
  * All coordinates and dimensions are in device pixels.
  */
 class EdgeEffect {
-public:
+ public:
+  // A wrapper class over the cc::Layer.
+  class LayerWrapper {
+   public:
+    virtual cc::Layer* layer() = 0;
+    virtual ~LayerWrapper() {}
+  };
+
   enum Edge {
     EDGE_TOP = 0,
     EDGE_LEFT,
@@ -33,7 +40,7 @@ public:
     EDGE_COUNT
   };
 
-  EdgeEffect(scoped_refptr<cc::Layer> edge, scoped_refptr<cc::Layer> glow);
+  EdgeEffect(scoped_ptr<LayerWrapper> edge, scoped_ptr<LayerWrapper> glow);
   ~EdgeEffect();
 
   void Pull(base::TimeTicks current_time, float delta_distance);
@@ -60,8 +67,8 @@ private:
     STATE_PULL_DECAY
   };
 
-  scoped_refptr<cc::Layer> edge_;
-  scoped_refptr<cc::Layer> glow_;
+  scoped_ptr<LayerWrapper> edge_;
+  scoped_ptr<LayerWrapper> glow_;
 
   float edge_alpha_;
   float edge_scale_y_;