Try to get rid of all direct references to particular native themes.

ui/views/widget/native_widget_aura.cc

Index: ui/views/widget/native_widget_aura.cc
diff --git a/ui/views/widget/native_widget_aura.cc b/ui/views/widget/native_widget_aura.cc
index 345ec9c431285011a9826b41163c27d7e90bffcc..a515e020b1e8eb5135d030d59c18dcfac36f1327 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -744,11 +744,7 @@ void NativeWidgetAura::SetVisibilityAnimationTransition(
 }
 
 ui::NativeTheme* NativeWidgetAura::GetNativeTheme() const {
-#if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)
-  return DesktopWindowTreeHost::GetNativeTheme(window_);
-#else
-  return ui::NativeThemeAura::instance();
-#endif
+  return ui::NativeTheme::GetInstanceForNativeUi();
 }
 
 void NativeWidgetAura::OnRootViewLayout() {