style: Remove -moz-user-disabled.

We treat it exactly the same as -moz-broken. The pseudo-class is not
exposed to content, so I don't think we have a reason to keep it around.

Differential Revision: https://phabricator.services.mozilla.com/D89904

components/style/gecko/non_ts_pseudo_class_list.rs

@@ -92,8 +92,6 @@ macro_rules! apply_non_ts_list {
                 ("-moz-meter-sub-optimum", MozMeterSubOptimum, IN_SUB_OPTIMUM_STATE, _),
                 ("-moz-meter-sub-sub-optimum", MozMeterSubSubOptimum, IN_SUB_SUB_OPTIMUM_STATE, _),
 
-                ("-moz-user-disabled", MozUserDisabled, IN_USER_DISABLED_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS_AND_CHROME),
-
                 ("-moz-first-node", MozFirstNode, _, _),
                 ("-moz-last-node", MozLastNode, _, _),
                 ("-moz-only-whitespace", MozOnlyWhitespace, _, _),

components/style/gecko/wrapper.rs

@@ -2029,7 +2029,6 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::Invalid |
             NonTSPseudoClass::MozUIValid |
             NonTSPseudoClass::MozBroken |
-            NonTSPseudoClass::MozUserDisabled |
             NonTSPseudoClass::MozSuppressed |
             NonTSPseudoClass::MozLoading |
             NonTSPseudoClass::MozHandlerBlocked |