Bug 1895391 - Remove widget.non-native-theme.solid-outline-style pref r=gregp,emilio

Differential Revision: https://phabricator.services.mozilla.com/D210276

modules/libpref/init/StaticPrefList.yaml

@@ -16210,12 +16210,6 @@
 #endif
   mirror: always
 
-# Whether the outline style should be one big stroke or two contrasting strokes
-- name: widget.non-native-theme.solid-outline-style
-  type: bool
-  value: false
-  mirror: always
-
 # Preference to disable dark scrollbar implementation.
 # This is mainly for testing because dark scrollbars have to be semi-
 # transparent, but many reftests expect scrollbars to look identical

widget/Theme.cpp

@@ -1350,7 +1350,6 @@ void Theme::PaintAutoStyleOutline(nsIFrame* aFrame,
                                   const LayoutDeviceRect& aRect,
                                   const Colors& aColors, DPIRatio aDpiRatio) {
   const auto& accentColor = aColors.Accent();
-  const bool solid = StaticPrefs::widget_non_native_theme_solid_outline_style();
   LayoutDeviceCoord strokeWidth(ThemeDrawing::SnapBorderWidth(2.0f, aDpiRatio));
 
   LayoutDeviceRect rect(aRect);
@@ -1410,10 +1409,6 @@ void Theme::PaintAutoStyleOutline(nsIFrame* aFrame,
                           : accentColor.Get();
   DrawRect(primaryColor);
 
-  if (solid) {
-    return;
-  }
-
   offset += strokeWidth;
 
   strokeWidth =
@@ -1486,9 +1481,7 @@ bool Theme::GetWidgetOverflow(nsDeviceContext* aContext, nsIFrame* aFrame,
   CSSIntMargin overflow;
   switch (aAppearance) {
     case StyleAppearance::FocusOutline: {
-      // 2px * one segment, or 2px + 1px
-      const auto width =
-          StaticPrefs::widget_non_native_theme_solid_outline_style() ? 2 : 3;
+      const auto width = 3;
       overflow.SizeTo(width, width, width, width);
       break;
     }