Revert of Calculate paint invalidation rect for scrollbars

third_party/WebKit/Source/platform/scroll/ScrollbarTheme.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 44 matching lines @@
     virtual int scrollbarMargin() const { return 0; }
 
     virtual ScrollbarButtonsPlacement buttonsPlacement() const { return ScrollbarButtonsPlacementSingle; }
 
     virtual bool supportsControlTints() const { return false; }
     virtual bool usesOverlayScrollbars() const { return false; }
     virtual void updateScrollbarOverlayStyle(const ScrollbarThemeClient*) { }
 
     virtual bool invalidateOnMouseEnterExit() { return false; }
 
+    void invalidateParts(ScrollbarThemeClient* scrollbar, ScrollbarControlPartMask mask)
+    {
+        if (mask & BackButtonStartPart)
+            invalidatePart(scrollbar, BackButtonStartPart);
+        if (mask & ForwardButtonStartPart)
+            invalidatePart(scrollbar, ForwardButtonStartPart);
+        if (mask & BackTrackPart)
+            invalidatePart(scrollbar, BackTrackPart);
+        if (mask & ThumbPart)
+            invalidatePart(scrollbar, ThumbPart);
+        if (mask & ForwardTrackPart)
+            invalidatePart(scrollbar, ForwardTrackPart);
+        if (mask & BackButtonEndPart)
+            invalidatePart(scrollbar, BackButtonEndPart);
+        if (mask & ForwardButtonEndPart)
+            invalidatePart(scrollbar, ForwardButtonEndPart);
+    }
+
+    virtual void invalidatePart(ScrollbarThemeClient*, ScrollbarPart);
+
     virtual void paintScrollCorner(GraphicsContext*, const DisplayItemClientWrapper&, const IntRect& cornerRect);
     virtual void paintTickmarks(GraphicsContext*, const ScrollbarThemeClient*, const IntRect&) { }
 
     virtual bool shouldCenterOnThumb(const ScrollbarThemeClient*, const PlatformMouseEvent&);
     virtual bool shouldSnapBackToDragOrigin(const ScrollbarThemeClient*, const PlatformMouseEvent&);
     virtual bool shouldDragDocumentInsteadOfThumb(const ScrollbarThemeClient*, const PlatformMouseEvent&) { return false; }
 
     // The position of the thumb relative to the track.
     virtual int thumbPosition(const ScrollbarThemeClient*);
     // The length of the thumb along the axis of the scrollbar.
@@ skipping 43 matching lines @@
     static DisplayItem::Type buttonPartToDisplayItemType(ScrollbarPart);
     static DisplayItem::Type trackPiecePartToDisplayItemType(ScrollbarPart);
 
 private:
     static ScrollbarTheme* nativeTheme(); // Must be implemented to return the correct theme subclass.
     static bool gMockScrollbarsEnabled;
 };
 
 }
 #endif