This CL adds support for extension in GYP.

test/ios/extension/ExtensionContainer/AppDelegate.m

+//
+//  AppDelegate.m
+//  ExtensionContainer
+//
+//  Created by Olivier Robin on 6/27/14.
+//  Copyright (c) 2014 Olivier Robin. All rights reserved.
+//
+
+#import "AppDelegate.h"
+
+@interface AppDelegate ()
+
+
+@end
+
+@implementation AppDelegate
+
+
+- (BOOL)application:(UIApplication *)application
+    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+  // Override point for customization after application launch.
+  return YES;
+}
+
+- (void)applicationWillResignActive:(UIApplication *)application {
+}
+
+- (void)applicationDidEnterBackground:(UIApplication *)application {
+}
+
+- (void)applicationWillEnterForeground:(UIApplication *)application {
+}
+
+- (void)applicationDidBecomeActive:(UIApplication *)application {
+}
+
+- (void)applicationWillTerminate:(UIApplication *)application {
+}
+
+@end