Add support for iOS WatchKit apps in GYP

test/ios/watch/WatchContainer/ViewController.m

 // Copyright (c) 2014 Google Inc. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ViewController.h"
 
 @interface ViewController ()
 
 
 @end
 
 @implementation ViewController
 
 - (void)viewDidLoad {
   [super viewDidLoad];
   // Do any additional setup after loading the view, typically from a nib.
 }
 
 - (void)didReceiveMemoryWarning {
   [super didReceiveMemoryWarning];
   // Dispose of any resources that can be recreated.
 }
 
 @end