gistfile1.txt

    GTMOAuth2ViewControllerTouch *viewController = [GTMOAuth2ViewControllerTouch controllerWithScope:scope
                                                                                            clientID:CLIENT_ID 
                                                                                        clientSecret:CLIENT_SECRET
                                                                                    keychainItemName:kKeychainItemName
                                                                                   completionHandler:completionHandler];

    UIViewController *parentViewController = viewController;
    if (![self.delegate isKindOfClass:[UINavigationController class]]) {
        self.navigationController = [[[UINavigationController alloc] initWithRootViewController:viewController] autorelease];
        self.navigationController.navigationBar.translucent = YES;
        
        UIBarButtonItem *leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self.delegate action:@selector(dismissViewControllerAnimated:completion:)];
        self.navigationController.navigationItem.leftBarButtonItem = leftBarButtonItem;
//        [leftBarButtonItem release];
        parentViewController = self.navigationController;
    }
    parentViewController.modalTransitionStyle = self.delegate.modalTransitionStyle;
    [self.delegate presentViewController:parentViewController animated:YES completion:^{
        NSLog(@"Google Sign In presented");
    }];