Bug 1854546 - Remove dom.focus.fixup pref r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D188929

layout/base/PresShell.cpp

@@ -1522,9 +1522,6 @@ void PresShell::AddAuthorSheet(StyleSheet* aSheet) {
 }
 
 bool PresShell::FixUpFocus() {
-  if (!StaticPrefs::dom_focus_fixup()) {
-    return false;
-  }
   if (NS_WARN_IF(!mDocument)) {
     return false;
   }

modules/libpref/init/StaticPrefList.yaml

@@ -2366,14 +2366,6 @@
   mirror: always
   rust: true
 
-# Controls whether the "focus fixup rule" is enabled. Subject to minor changes
-# based on https://github.com/whatwg/html/pull/8392 and
-# https://github.com/whatwg/html/issues/8225
-- name: dom.focus.fixup
-  type: bool
-  value: true
-  mirror: always
-
 - name: dom.mouse_capture.enabled
   type: bool
   value: true

testing/web-platform/meta/css/css-contain/container-queries/__dir__.ini

@@ -1 +0,0 @@
-prefs: [layout.css.container-queries.enabled:true, dom.focus.fixup:true]

testing/web-platform/meta/css/selectors/__dir__.ini

@@ -1,3 +1,3 @@
 lsan-disabled: true
-prefs: [gfx.font_rendering.fallback.async:false, layout.css.has-selector.enabled:true, dom.focus.fixup:true]
+prefs: [gfx.font_rendering.fallback.async:false, layout.css.has-selector.enabled:true]
 leak-threshold: [default:3276800, tab:460800]

testing/web-platform/meta/shadow-dom/focus/__dir__.ini

@@ -1 +0,0 @@
-prefs: [dom.focus.fixup:true]

toolkit/components/prompts/test/test_modal_prompts.html

@@ -22,12 +22,6 @@ async function runTests(util) {
     "resource://gre/modules/NetUtil.sys.mjs"
   );
 
-  // The ConfirmEx + delay test has slightly different behavior with the focus
-  // fixup rule vs. without.
-  await SpecialPowers.pushPrefEnv({
-    set: [["dom.focus.fixup", true]],
-  });
-
   let state, action, promptDone;
 
   let checkVal = {};