Overlay scrollbars flush with window edge

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

 /*
  * Copyright (c) 2009, Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 53 matching lines @@
   void paintButton(GraphicsContext&,
                    const Scrollbar&,
                    const IntRect&,
                    ScrollbarPart) override;
   void paintThumb(GraphicsContext&, const Scrollbar&, const IntRect&) override;
 
   bool shouldRepaintAllPartsOnInvalidation() const override;
   ScrollbarPart invalidateOnThumbPositionChange(
       const ScrollbarThemeClient&,
       float oldPosition,
-      float newPosition) const override;
+      float newPosition,
+      bool hitBeginOrEndChanged) const override;
 
  private:
   FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, ButtonSizeHorizontal);
   FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, ButtonSizeVertical);
   FRIEND_TEST_ALL_PREFIXES(ScrollbarThemeAuraTest, NoButtonsReturnsSize0);
 
   virtual bool hasScrollbarButtons(ScrollbarOrientation) const;
   IntSize buttonSize(const ScrollbarThemeClient&);
 };
 
 }  // namespace blink
 
 #endif