Bug 1675389 - Tweak the baseline of checkbox/radio buttons on the non-native theme. r=spohl

Differential Revision: https://phabricator.services.mozilla.com/D102478

widget/nsNativeBasicTheme.cpp

@@ -1332,6 +1332,11 @@ LayoutDeviceIntMargin nsNativeBasicTheme::GetWidgetBorder(
       LayoutDeviceIntCoord w = (kButtonBorderWidth * dpiRatio).Rounded();
       return LayoutDeviceIntMargin(w, w, w, w);
     }
+    case StyleAppearance::Checkbox:
+    case StyleAppearance::Radio: {
+      LayoutDeviceIntCoord w = (kCheckboxRadioBorderWidth * dpiRatio).Rounded();
+      return LayoutDeviceIntMargin(w, w, w, w);
+    }
     default:
       return LayoutDeviceIntMargin();
   }

widget/nsNativeBasicTheme.h

@@ -117,6 +117,10 @@ static const CSSCoord kRangeHeight = 6.0f;
 static const CSSCoord kProgressbarHeight = 6.0f;
 static const CSSCoord kMeterHeight = 12.0f;
 
+// nsCheckboxRadioFrame takes the bottom of the content box as the baseline.
+// This border-width makes its baseline 2px under the bottom, which is nice.
+static const CSSCoord kCheckboxRadioBorderWidth = 2.0f;
+
 }  // namespace widget
 }  // namespace mozilla