Cherry-pick 30cda07. rdar://122956268

    Handle <input type=checkbox switch> disabled styling as part of the painting code
    https://bugs.webkit.org/show_bug.cgi?id=269378
    rdar://122956268

    Reviewed by Aditya Keerthi.

    Using opacity creates a stacking context which is not desirable.

    * LayoutTests/platform/ios-wk2/TestExpectations:
    * Source/WebCore/rendering/ios/RenderThemeIOS.mm:
    (WebCore::RenderThemeIOS::adjustSwitchStyle const):

    Canonical link: https://commits.webkit.org/275002@main

Identifier: 272448.652@safari-7618-branch

Source/WebCore/rendering/RenderThemeIOS.mm

@@ -721,7 +721,7 @@ static bool renderThemePaintSwitchTrack(OptionSet<ControlStyle::State>, const Re
 }
 #endif
 
-void RenderThemeIOS::adjustSwitchStyle(RenderStyle& style, const Element* element) const
+void RenderThemeIOS::adjustSwitchStyle(RenderStyle& style, const Element*) const
 {
     // FIXME: Deduplicate sizing with the generic code somehow.
     if (style.width().isAuto() || style.height().isAuto()) {
@@ -733,9 +733,6 @@ static bool renderThemePaintSwitchTrack(OptionSet<ControlStyle::State>, const Re
 
     if (style.outlineStyleIsAuto() == OutlineIsAuto::On)
         style.setOutlineStyle(BorderStyle::None);
-
-    if (element->isDisabledFormControl())
-        style.setOpacity(.4f);
 }
 
 bool RenderThemeIOS::paintSwitchThumb(const RenderObject& renderer, const PaintInfo& paintInfo, const FloatRect& rect)