Overlay scrollbars flush with window edge

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

 /*
  * Copyright (c) 2008, 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 296 matching lines @@
 }
 
 bool ScrollbarThemeAura::shouldRepaintAllPartsOnInvalidation() const {
   // This theme can separately handle thumb invalidation.
   return false;
 }
 
 ScrollbarPart ScrollbarThemeAura::invalidateOnThumbPositionChange(
     const ScrollbarThemeClient& scrollbar,
     float oldPosition,
-    float newPosition) const {
+    float newPosition,
+    bool hitBeginOrEndChanged) const {
   ScrollbarPart invalidParts = NoPart;
   ASSERT(buttonsPlacement() == WebScrollbarButtonsPlacementSingle);
   static const ScrollbarPart kButtonParts[] = {BackButtonStartPart,
                                                ForwardButtonEndPart};
   for (ScrollbarPart part : kButtonParts) {
     if (buttonPartPaintingParams(scrollbar, oldPosition, part) !=
         buttonPartPaintingParams(scrollbar, newPosition, part))
       invalidParts = static_cast<ScrollbarPart>(invalidParts | part);
   }
   return invalidParts;
 }
 
 bool ScrollbarThemeAura::hasScrollbarButtons(
     ScrollbarOrientation orientation) const {
   WebThemeEngine* themeEngine = Platform::current()->themeEngine();
   if (orientation == VerticalScrollbar) {
     return !themeEngine->getSize(WebThemeEngine::PartScrollbarDownArrow)
                 .isEmpty();
   }
   return !themeEngine->getSize(WebThemeEngine::PartScrollbarLeftArrow)
               .isEmpty();
-};
+}
 
 IntSize ScrollbarThemeAura::buttonSize(const ScrollbarThemeClient& scrollbar) {
   if (!hasScrollbarButtons(scrollbar.orientation()))
     return IntSize(0, 0);
 
   if (scrollbar.orientation() == VerticalScrollbar) {
     int squareSize = scrollbar.width();
     return IntSize(squareSize, scrollbar.height() < 2 * squareSize
                                    ? scrollbar.height() / 2
                                    : squareSize);
   }
 
   // HorizontalScrollbar
   int squareSize = scrollbar.height();
   return IntSize(
       scrollbar.width() < 2 * squareSize ? scrollbar.width() / 2 : squareSize,
       squareSize);
 }
 
 }  // namespace blink