temporary measure against infinite loop after browser_bug380960.js (bug 585361)

testing/mochitest/browser-test.js

@@ -83,6 +83,10 @@ Tester.prototype = {
         let msg = baseMsg.replace("{elt}", "tab") +
                   ": " + lastTab.linkedBrowser.currentURI.spec;
         this.currentTest.addResult(new testResult(false, msg, "", false));
+        if (gBrowser._removingTabs && gBrowser._removingTabs.indexOf(lastTab) > -1) {
+          gBrowser._endRemoveTab(lastTab);
+          continue;
+        }
         gBrowser.removeTab(lastTab);
       }
     }