Add missing goog.require statements.

Author: jleyba

Diff for: javascript/atoms/locators/classname.js

@@ -15,6 +15,8 @@
 
 goog.provide('bot.locators.className');
 
+goog.require('bot.Error');
+goog.require('bot.ErrorCode');
 goog.require('goog.array');
 goog.require('goog.dom');
 goog.require('goog.dom.DomHelper');