Aura overlay scrollbars adjust color for dark backgrounds

content/child/webthemeengine_impl_default.cc

Index: content/child/webthemeengine_impl_default.cc
diff --git a/content/child/webthemeengine_impl_default.cc b/content/child/webthemeengine_impl_default.cc
index 7fa4ba7d6497c2d374257db255e91d283d2c24cc..20f205cd03e264dea714d12a5ad323845ef92141 100644
--- a/content/child/webthemeengine_impl_default.cc
+++ b/content/child/webthemeengine_impl_default.cc
@@ -8,7 +8,6 @@
 #include "skia/ext/platform_canvas.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
-#include "ui/native_theme/native_theme.h"
 
 using blink::WebCanvas;
 using blink::WebColor;
@@ -177,6 +176,18 @@ static void GetNativeThemeExtraParams(
       native_theme_extra_params->progress_bar.value_rect_height =
           extra_params->progressBar.valueRectHeight;
       break;
+    case WebThemeEngine::PartScrollbarHorizontalThumb:
+    case WebThemeEngine::PartScrollbarVerticalThumb:
+      if (extra_params) {
+        native_theme_extra_params->scrollbar_style =
+            static_cast<ui::NativeTheme::ScrollbarOverlayStyle>(
+                extra_params->scrollbarStyle);
+      } else {
+        native_theme_extra_params->scrollbar_style = ui::NativeTheme::
+            ScrollbarOverlayStyle::ScrollbarOverlayStyleDefault;
+      }
+
+      break;
     default:
       break;  // Parts that have no extra params get here.
   }
@@ -221,15 +232,17 @@ void WebThemeEngineImpl::paint(
       native_theme_extra_params);
 }
 
-void WebThemeEngineImpl::paintStateTransition(blink::WebCanvas* canvas,
-                                              WebThemeEngine::Part part,
-                                              WebThemeEngine::State startState,
-                                              WebThemeEngine::State endState,
-                                              double progress,
-                                              const blink::WebRect& rect) {
+void WebThemeEngineImpl::paintStateTransition(
+    blink::WebCanvas* canvas,
+    WebThemeEngine::Part part,
+    WebThemeEngine::State startState,
+    WebThemeEngine::State endState,
+    double progress,
+    const blink::WebRect& rect,
+    ui::NativeTheme::ScrollbarOverlayStyle style) {
   ui::NativeTheme::GetInstanceForWeb()->PaintStateTransition(
       canvas, NativeThemePart(part), NativeThemeState(startState),
-      NativeThemeState(endState), progress, gfx::Rect(rect));
+      NativeThemeState(endState), progress, gfx::Rect(rect), style);
 }
 
 #if defined(OS_WIN)