Added more typechecking functions and unit tests for existing code.

remoting/webapp/crd/js/gnubby_auth_handler.js

Index: remoting/webapp/crd/js/gnubby_auth_handler.js
diff --git a/remoting/webapp/crd/js/gnubby_auth_handler.js b/remoting/webapp/crd/js/gnubby_auth_handler.js
index 4d414daab7c98d05e7f9a10d11319006fd0b2184..cf3ed9c3cd65c43d50182c04889425fbd813985e 100644
--- a/remoting/webapp/crd/js/gnubby_auth_handler.js
+++ b/remoting/webapp/crd/js/gnubby_auth_handler.js
@@ -53,13 +53,13 @@ remoting.GnubbyAuthHandler.prototype.sendMessageToHost_ = function(data) {
  * @param {string} data The gnubby-auth message data.
  */
 remoting.GnubbyAuthHandler.prototype.onMessage = function(data) {
-  var message = getJsonObjectFromString(data);
-  var messageType = getStringAttr(message, 'type');
+  var message = base.getJsonObjectFromString(data);
+  var messageType = base.getStringAttr(message, 'type');
   if (messageType == 'data') {
     this.sendMessageToGnubbyd_({
       'type': 'auth-agent@openssh.com',
-      'data': getArrayAttr(message, 'data')
-    }, this.callback_.bind(this, getNumberAttr(message, 'connectionId')));
+      'data': base.getArrayAttr(message, 'data')
+    }, this.callback_.bind(this, base.getNumberAttr(message, 'connectionId')));
   } else {
     console.error('Invalid gnubby-auth message: ' + messageType);
   }
@@ -77,7 +77,7 @@ remoting.GnubbyAuthHandler.prototype.callback_ =
     this.sendMessageToHost_({
       'type': 'data',
       'connectionId': connectionId,
-      'data': getArrayAttr(response, 'data')
+      'data': base.getArrayAttr(response, 'data')
     });
   } catch (/** @type {*} */ err) {
     console.error('gnubby callback failed: ', err);