Don't use letters in me2mom access code.

remoting/webapp/me2mom/remoting.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // TODO(ajwong): This seems like a bad idea to share the exact same object
 // with the background page.  Why are we doing it like this?
 var remoting = chrome.extension.getBackgroundPage().remoting;
 
 XMPP_LOGIN_NAME = 'xmpp_login';
 XMPP_TOKEN_NAME = 'xmpp_token';
@@ skipping 245 matching lines @@
     var host = JSON.parse(xhr.responseText);
     if (host.data && host.data.jabberId) {
       remoting.hostjid = host.data.jabberId;
       startSession_();
       return;
     }
   }
   showConnectError_(xhr.status, xhr.responseText);
 }
 
+function normalizeAccessCode(accessCode) {
+  // Trim whitespace from beginning and the end.
+  // TODO(sergeyu): Do we need to do any other normalization here?
+  return accessCode.replace(/^\s+|\s+$/, '');
+}
+
 function resolveSupportId(support_id) {
     var xhr = new XMLHttpRequest();
     xhr.onreadystatechange = function() {
       if (xhr.readyState != 4) {
         return;
       }
       parseServerResponse_(xhr);
     };
 
     xhr.open('GET',
              'https://www.googleapis.com/chromoting/v1/support-hosts/' +
                  encodeURIComponent(support_id),
              true);
     xhr.setRequestHeader('Authorization',
                          'OAuth ' + remoting.oauth2.getAccessToken());
     xhr.send(null);
 }
 
 function tryConnect(form) {
-  remoting.accessCode = form['access_code_entry'].value;
+  remoting.accessCode = normalizeAccessCode(form['access_code_entry'].value);
   // TODO(jamiewalch): Since the mapping from (SupportId, HostSecret) to
   // AccessCode is not yet defined, assume it's hyphen-separated for now.
   var parts = remoting.accessCode.split('-');
   if (parts.length != 2) {
     showConnectError_(404);
   } else {
     setClientMode('connecting');
     if (remoting.oauth2.needsNewAccessToken()) {
       remoting.oauth2.refreshAccessToken(function() {
         resolveSupportId(parts[0]);
       });
       return;
     } else {
       resolveSupportId(parts[0]);
     }
   }
 }
 
 function cancelConnect() {
   remoting.accessCode = '';
   setClientMode('unconnected');
 }