Aura overlay scrollbars adjust color for dark backgrounds

content/child/webthemeengine_impl_default.h

Index: content/child/webthemeengine_impl_default.h
diff --git a/content/child/webthemeengine_impl_default.h b/content/child/webthemeengine_impl_default.h
index 36ddb6bf7f569f0b8b67eeea0580f7b9b12d0834..cf1eda10508142f83d1ebdc179b0480df5eede72 100644
--- a/content/child/webthemeengine_impl_default.h
+++ b/content/child/webthemeengine_impl_default.h
@@ -21,12 +21,6 @@ class WebThemeEngineImpl : public blink::WebThemeEngine {
              blink::WebThemeEngine::State state,
              const blink::WebRect& rect,
              const blink::WebThemeEngine::ExtraParams* extra_params) override;
-  virtual void paintStateTransition(blink::WebCanvas* canvas,
-                                    blink::WebThemeEngine::Part part,
-                                    blink::WebThemeEngine::State startState,
-                                    blink::WebThemeEngine::State endState,
-                                    double progress,
-                                    const blink::WebRect& rect);
 #if defined(OS_WIN)
   // Caches the scrollbar metrics. These are retrieved in the browser and passed
   // to the renderer in RendererPreferences because the required Windows system