Aura overlay scrollbars adjust color for dark backgrounds

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

Index: third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
diff --git a/third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp b/third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
index ed95ef9da96d7e9a04faeb27a7477c5350655248..b60cfbcbfbea6ef5c5a60358ba6299897314ea72 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
+++ b/third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp
@@ -162,8 +162,13 @@ void ScrollbarThemeOverlay::paintThumb(GraphicsContext& context,
   if (scrollbar.orientation() == VerticalScrollbar)
     part = WebThemeEngine::PartScrollbarVerticalThumb;
 
+  blink::WebThemeEngine::ExtraParams params;
+  params.scrollbarThumb.scrollbarTheme =
+      static_cast<WebScrollbarOverlayColorTheme>(
+          scrollbar.getScrollbarOverlayColorTheme());
+
   Platform::current()->themeEngine()->paint(canvas, part, state, WebRect(rect),
-                                            0);
+                                            &params);
 }
 
 ScrollbarPart ScrollbarThemeOverlay::hitTest(