Bug 1702556: fix eslint browser/extensions/screenshots/build/selection.js r=emalysz

Differential Revision: https://phabricator.services.mozilla.com/D110736

browser/extensions/screenshots/build/selection.js

@@ -2,7 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-this.selection = (function () {let exports={}; class Selection {
+this.selection = (function() {
+  let exports = {};
+  class Selection {
     constructor(x1, y1, x2, y2) {
       this.x1 = x1;
       this.y1 = y1;
@@ -113,13 +115,12 @@ this.selection = (function () {let exports={}; class Selection {
       }
       return new Selection(rect.left, rect.top, rect.right, rect.bottom);
     }
-}
+  }
 
-if (typeof exports !== "undefined") {
+  if (typeof exports !== "undefined") {
     exports.Selection = Selection;
-}
+  }
 
-return exports;
+  return exports;
 })();
 null;
-