refactor: adopt hideCSS helper for eejsBlock_styles

disable_chat.js

@@ -1,12 +1,13 @@
 'use strict';
 
-exports.eejsBlock_styles = (hookName, context, cb) => {
-  context.content += `<style>
-    .hide-for-mobile { display:none !important; }
-    #chaticon, #chatbox { display: none !important; }
+const {hideCSS} = require('ep_plugin_helpers');
+
+exports.eejsBlock_styles = hideCSS('.hide-for-mobile, #chaticon, #chatbox', {
+  // Once chat is hidden the users panel takes over the full popup; without
+  // these height rules the popup collapses to the (now-empty) chat region.
+  extra: `
     #users { height:100%; }
     .popup#users.chatAndUsers > .popup-content { height:100%; }
     .popup#users.chatAndUsers { height:100%; }
-  </style>`;
-  cb();
-};
+  `,
+});

package.json

@@ -29,5 +29,8 @@
   "repository": {
     "type": "git",
     "url": "https://github.com/ether/ep_disable_chat"
+  },
+  "dependencies": {
+    "ep_plugin_helpers": "^0.5.0"
   }
 }