chromium support

content.js

@@ -1,6 +1,8 @@
 (function () {
   "use strict";
 
+  const api = typeof browser === "object" ? browser : chrome;
+
   const EXCLUDED_ANCESTORS = "head, script, style, noscript, template, textarea, select, option";
   const FONT_FAMILIES = Object.freeze({
     round: '"Glagolify Shafarik Round"',
@@ -330,14 +332,15 @@
     return { enabled };
   }
 
-  browser.runtime.onMessage.addListener((message) => {
+  api.runtime.onMessage.addListener((message, sender, sendResponse) => {
     if (!message || message.type !== "glagolify:set-enabled" || typeof message.enabled !== "boolean") {
-      return undefined;
+      return false;
     }
-    return Promise.resolve(setEnabled(message.enabled, message.fontStyle));
+    sendResponse(setEnabled(message.enabled, message.fontStyle));
+    return false;
   });
 
-  browser.runtime.sendMessage({ type: "glagolify:document-ready" })
+  api.runtime.sendMessage({ type: "glagolify:document-ready" })
     .then((response) => {
       setEnabled(Boolean(response && response.enabled), response && response.fontStyle);
     })