Aura overlay scrollbars adjust color for dark backgrounds

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 301 matching lines @@
                                      ScrollbarPart part) {
   DisplayItem::Type displayItemType = buttonPartToDisplayItemType(part);
   if (DrawingRecorder::useCachedDrawingIfPossible(gc, scrollbar,
                                                   displayItemType))
     return;
   PartPaintingParams params =
       buttonPartPaintingParams(scrollbar, scrollbar.currentPos(), part);
   if (!params.shouldPaint)
     return;
   DrawingRecorder recorder(gc, scrollbar, displayItemType, rect);
-  Platform::current()->themeEngine()->paint(gc.canvas(), params.part,
-                                            params.state, WebRect(rect), 0);
+  Platform::current()->themeEngine()->paint(
+      gc.canvas(), params.part, params.state, WebRect(rect), nullptr);
 }
 
 void ScrollbarThemeAura::paintThumb(GraphicsContext& gc,
                                     const Scrollbar& scrollbar,
                                     const IntRect& rect) {
   if (DrawingRecorder::useCachedDrawingIfPossible(gc, scrollbar,
                                                   DisplayItem::kScrollbarThumb))
     return;
 
   DrawingRecorder recorder(gc, scrollbar, DisplayItem::kScrollbarThumb, rect);
 
   WebThemeEngine::State state;
   WebCanvas* canvas = gc.canvas();
   if (scrollbar.pressedPart() == ThumbPart)
     state = WebThemeEngine::StatePressed;
   else if (scrollbar.hoveredPart() == ThumbPart)
     state = WebThemeEngine::StateHover;
   else
     state = WebThemeEngine::StateNormal;
+
   Platform::current()->themeEngine()->paint(
       canvas, scrollbar.orientation() == HorizontalScrollbar
                   ? WebThemeEngine::PartScrollbarHorizontalThumb
                   : WebThemeEngine::PartScrollbarVerticalThumb,
-      state, WebRect(rect), 0);
+      state, WebRect(rect), nullptr);
 }
 
 bool ScrollbarThemeAura::shouldRepaintAllPartsOnInvalidation() const {
   // This theme can separately handle thumb invalidation.
   return false;
 }
 
 ScrollbarPart ScrollbarThemeAura::invalidateOnThumbPositionChange(
     const ScrollbarThemeClient& scrollbar,
     float oldPosition,
@@ skipping 33 matching lines @@
   }
 
   // HorizontalScrollbar
   int squareSize = scrollbar.height();
   return IntSize(
       scrollbar.width() < 2 * squareSize ? scrollbar.width() / 2 : squareSize,
       squareSize);
 }
 
 }  // namespace blink