Bug 1229224: Bustage fix for browser-social.js

--HG--
extra : commitid : 2aNdGN3Mgo1

browser/base/content/browser-social.js

@@ -1359,7 +1359,8 @@ SocialMarks = {
     let providers = this.getProviders();
 
     // remove all previous entries by class
-    for (let m of document.getElementsByClassName("context-socialmarks")) {
+    let menus = [...document.getElementsByClassName("context-socialmarks")];
+    for (let m of menus) {
       m.parentNode.removeChild(m);
     }