Scrollbar Layer revert

cc/layers/scrollbar_layer.h

Index: cc/layers/scrollbar_layer.h
===================================================================
--- cc/layers/scrollbar_layer.h	(revision 215030)
+++ cc/layers/scrollbar_layer.h	(working copy)
@@ -10,9 +10,10 @@
 #include "cc/layers/contents_scaling_layer.h"
 #include "cc/layers/scrollbar_theme_painter.h"
 #include "cc/resources/layer_updater.h"
-#include "cc/resources/scoped_ui_resource.h"
 
 namespace cc {
+class CachingBitmapContentLayerUpdater;
+class ResourceUpdateQueue;
 class ScrollbarThemeComposite;
 
 class CC_EXPORT ScrollbarLayer : public ContentsScalingLayer {
@@ -32,6 +33,8 @@
   ScrollbarOrientation Orientation() const;
 
   // Layer interface
+  virtual void SetTexturePriorities(const PriorityCalculator& priority_calc)
+      OVERRIDE;
   virtual bool Update(ResourceUpdateQueue* queue,
                       const OcclusionTracker* occlusion) OVERRIDE;
   virtual void SetLayerTreeHost(LayerTreeHost* host) OVERRIDE;
@@ -52,26 +55,37 @@
   virtual ~ScrollbarLayer();
 
  private:
+  bool UpdatePart(CachingBitmapContentLayerUpdater* painter,
+                  LayerUpdater::Resource* resource,
+                  gfx::Rect rect,
+                  ResourceUpdateQueue* queue);
+  void CreateUpdaterIfNeeded();
   gfx::Rect ScrollbarLayerRectToContentRect(gfx::Rect layer_rect) const;
   gfx::Rect OriginThumbRect() const;
 
+  bool is_dirty() const { return !dirty_rect_.IsEmpty(); }
+
   int MaxTextureSize();
   float ClampScaleToMaxTextureSize(float scale);
 
-  scoped_refptr<UIResourceBitmap> RasterizeTrack();
-  scoped_refptr<UIResourceBitmap> RasterizeThumb();
-
   scoped_ptr<Scrollbar> scrollbar_;
 
   int thumb_thickness_;
   int thumb_length_;
   gfx::Rect track_rect_;
-  gfx::Rect thumb_rect_;
   int scroll_layer_id_;
 
-  scoped_ptr<ScopedUIResource> track_resource_;
-  scoped_ptr<ScopedUIResource> thumb_resource_;
+  unsigned texture_format_;
 
+  gfx::RectF dirty_rect_;
+
+  scoped_refptr<CachingBitmapContentLayerUpdater> track_updater_;
+  scoped_refptr<CachingBitmapContentLayerUpdater> thumb_updater_;
+
+  // All the parts of the scrollbar except the thumb
+  scoped_ptr<LayerUpdater::Resource> track_;
+  scoped_ptr<LayerUpdater::Resource> thumb_;
+
   DISALLOW_COPY_AND_ASSIGN(ScrollbarLayer);
 };