Revert of Calculate paint invalidation rect for scrollbars

third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm

 /*
  * Copyright (C) 2010, 2011 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 421 matching lines @@
         [_scrollbarPainter.get() setTrackAlpha:currentValue];
         break;
     case UIStateTransition:
         [_scrollbarPainter.get() setUiStateTransitionProgress:currentValue];
         break;
     case ExpansionTransition:
         [_scrollbarPainter.get() setExpansionTransitionProgress:currentValue];
         break;
     }
 
-    _scrollbar->setNeedsPaintInvalidation();
+    _scrollbar->invalidate();
 }
 
 - (void)invalidate
 {
     BEGIN_BLOCK_OBJC_EXCEPTIONS;
     [self stopAnimation];
     END_BLOCK_OBJC_EXCEPTIONS;
     _scrollbar = 0;
 }
 
@@ skipping 617 matching lines @@
 
     ScrollbarThemeMacOverlayAPI* macTheme = macOverlayScrollbarTheme();
     if (!macTheme) {
         m_needsScrollerStyleUpdate = false;
         return;
     }
 
     NSScrollerStyle newStyle = [m_scrollbarPainterController.get() scrollerStyle];
 
     if (Scrollbar* verticalScrollbar = scrollableArea()->verticalScrollbar()) {
-        verticalScrollbar->setNeedsPaintInvalidation();
+        verticalScrollbar->invalidate();
 
         ScrollbarPainter oldVerticalPainter = [m_scrollbarPainterController.get() verticalScrollerImp];
         ScrollbarPainter newVerticalPainter = [NSClassFromString(@"NSScrollerImp") scrollerImpWithStyle:newStyle
                                                                                     controlSize:(NSControlSize)verticalScrollbar->controlSize()
                                                                                     horizontal:NO
                                                                                     replacingScrollerImp:oldVerticalPainter];
         [m_scrollbarPainterController.get() setVerticalScrollerImp:newVerticalPainter];
         macTheme->setNewPainterForScrollbar(verticalScrollbar, newVerticalPainter);
 
         // The different scrollbar styles have different thicknesses, so we must re-set the
         // frameRect to the new thickness, and the re-layout below will ensure the position
         // and length are properly updated.
         int thickness = macTheme->scrollbarThickness(verticalScrollbar->controlSize());
         verticalScrollbar->setFrameRect(IntRect(0, 0, thickness, thickness));
     }
 
     if (Scrollbar* horizontalScrollbar = scrollableArea()->horizontalScrollbar()) {
-        horizontalScrollbar->setNeedsPaintInvalidation();
+        horizontalScrollbar->invalidate();
 
         ScrollbarPainter oldHorizontalPainter = [m_scrollbarPainterController.get() horizontalScrollerImp];
         ScrollbarPainter newHorizontalPainter = [NSClassFromString(@"NSScrollerImp") scrollerImpWithStyle:newStyle
                                                                                     controlSize:(NSControlSize)horizontalScrollbar->controlSize()
                                                                                     horizontal:YES
                                                                                     replacingScrollerImp:oldHorizontalPainter];
         [m_scrollbarPainterController.get() setHorizontalScrollerImp:newHorizontalPainter];
         macTheme->setNewPainterForScrollbar(horizontalScrollbar, newHorizontalPainter);
 
         // The different scrollbar styles have different thicknesses, so we must re-set the
@@ skipping 63 matching lines @@
         return;
 
     m_visibleScrollerThumbRect = rectInViewCoordinates;
 }
 
 bool ScrollAnimatorMac::canUseCoordinatedScrollbar() {
     return ScrollbarThemeMacCommon::isOverlayAPIAvailable();
 }
 
 } // namespace blink