transition patch is redundant in Chrome 93+

content/style-injector.js

@@ -15,7 +15,7 @@ window.StyleInjector = window.INJECTED === 1 ? window.StyleInjector : ({
   const list = [];
   const table = new Map();
   let isEnabled = true;
-  let isTransitionPatched;
+  let isTransitionPatched = chrome.app && CSS.supports('accent-color', 'red'); // Chrome 93
   let exposeStyleName;
   // will store the original method refs because the page can override them
   let creationDoc, createElement, createElementNS;

global.css

@@ -1,8 +1,11 @@
-html#stylus #header *:not(#\1transition-suppressor) {
+@supports not (accent-color: red) {
   /* This suppresses a bug in all? browsers: they apply transitions during page load.
+   * It was fixed by crrev.com/886802 in Chrome 93, which we detect via `accent-color`.
    * Using an increased specificity to override sane selectors in user styles.
    * Using \1 to simplify js code because \0 is converted to \xFFFD per spec. */
-  transition: none !important;
+  html#stylus #header *:not(#\1transition-suppressor) {
+    transition: none !important;
+  }
 }
 :root {
   --family: Arial, "Helvetica Neue", Helvetica, system-ui, sans-serif;

js/dom-on-load.js

@@ -1,5 +1,5 @@
 /* global $$ $ $create focusAccessibility getEventKeyName moveFocus */// dom.js
-/* global clamp debounce */// toolbox.js
+/* global CHROME clamp debounce */// toolbox.js
 /* global msg */
 /* global t */// localization.js
 'use strict';
@@ -24,11 +24,13 @@
     }
   });
   // Removing transition-suppressor rule
-  const {sheet} = $('link[href$="global.css"]');
-  for (let i = 0, rule; (rule = sheet.cssRules[i]); i++) {
-    if (/#\\1\s?transition-suppressor/.test(rule.selectorText)) {
-      sheet.deleteRule(i);
-      break;
+  if (!CHROME || CHROME < 93) {
+    const {sheet} = $('link[href$="global.css"]');
+    for (let i = 0, rule; (rule = sheet.cssRules[i]); i++) {
+      if (/#\\1\s?transition-suppressor/.test(rule.cssText)) {
+        sheet.deleteRule(i);
+        break;
+      }
     }
   }