Bug 1535949 - browser.js: Fix typo in the identifier r=JanH

Differential Revision: https://phabricator.services.mozilla.com/D23812

--HG--
extra : moz-landing-system : lando

mobile/android/chrome/content/browser.js

@@ -1325,7 +1325,7 @@ var BrowserApp = {
     }
     this._tabs[toPosition] = movedTab;
 
-    let evt = new UIEvent("TabMove", {"bubbles":true, "cancellable":false, "view":window, "detail":fromPosition});
+    let evt = new UIEvent("TabMove", {"bubbles":true, "cancelable":false, "view":window, "detail":fromPosition});
     this.tabs[toPosition].browser.dispatchEvent(evt);
   },