Fix overflow:overlay scrollbar width for paint.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 336 matching lines @@
 
   bool inResizeMode() const { return m_inResizeMode; }
   void setInResizeMode(bool inResizeMode) { m_inResizeMode = inResizeMode; }
 
   LayoutUnit scrollWidth() const;
   LayoutUnit scrollHeight() const;
   int pixelSnappedScrollWidth() const;
   int pixelSnappedScrollHeight() const;
 
   int verticalScrollbarWidth(
-      OverlayScrollbarClipBehavior = IgnoreOverlayScrollbarSize) const override;
+      OverlayScrollbarClipBehavior =
+          IgnorePlatformOverlayScrollbarSize) const override;
   int horizontalScrollbarHeight(
-      OverlayScrollbarClipBehavior = IgnoreOverlayScrollbarSize) const override;
+      OverlayScrollbarClipBehavior =
+          IgnorePlatformOverlayScrollbarSize) const override;
 
   DoubleSize adjustedScrollOffset() const {
     return toDoubleSize(DoublePoint(scrollOrigin()) + m_scrollOffset);
   }
 
   void positionOverflowControls();
 
   // isPointInResizeControl() is used for testing if a pointer/touch position is
   // in the resize control area.
   bool isPointInResizeControl(const IntPoint& absolutePoint,
@@ skipping 230 matching lines @@
 
 DEFINE_TYPE_CASTS(PaintLayerScrollableArea,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->isPaintLayerScrollableArea(),
                   scrollableArea.isPaintLayerScrollableArea());
 
 }  // namespace blink
 
 #endif  // LayerScrollableArea_h