youtubeOAuthGoogApps.js

function youtube(){
  // Setup OAuthServiceConfig
  var oAuthConfig = UrlFetchApp.addOAuthService("youtube");
  oAuthConfig.setAccessTokenUrl("https://www.google.com/accounts/OAuthGetAccessToken");
  oAuthConfig.setRequestTokenUrl("https://www.google.com/accounts/OAuthGetRequestToken?scope=http%3A%2F%2Fgdata.youtube.com%2F");
  oAuthConfig.setAuthorizationUrl("https://www.google.com/accounts/OAuthAuthorizeToken");
  oAuthConfig.setConsumerKey("anonymous");
  oAuthConfig.setConsumerSecret("anonymous");

  // Setup optional parameters to point request at OAuthConfigService.  The "twitter"
  // value matches the argument to "addOAuthService" above.
  var options =
    {
      "oAuthServiceName" : "youtube",
      "oAuthUseToken" : "always"

     // "scope" : "http://gdata.youtube.com"
    };

 var result = UrlFetchApp.fetch("http://gdata.youtube.com/feeds/api/users/default/favorites?v=2&alt=json", options);
  var o  = Utilities.jsonParse(result.getContentText());

  Logger.log(o)
}