Beginning of restoring native caption bars

Author: K4sum1

widget/uikit/nsLookAndFeel.mm

@@ -275,6 +275,11 @@ static nscolor GetColorFromUIColor(UIColor* aColor) {
     case IntID::TreeScrollLinesMax:
       aResult = 3;
       break;
+    case IntID::DWMCompositor:
+    case IntID::WindowsClassic:
+      aResult = 0;
+      res = NS_ERROR_NOT_IMPLEMENTED;
+      break;
     case IntID::TabFocusModel:
       aResult = 1;  // default to just textboxes
       break;