Annotates functions returning retained objects.

ios/public/provider/chrome/browser/updatable_resource_provider.h

 // Copyright 2015 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.
 
 #ifndef IOS_PUBLIC_PROVIDER_CHROME_BROWSER_UPDATABLE_RESOURCE_PROVIDER_H_
 #define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_UPDATABLE_RESOURCE_PROVIDER_H_
 
 #import <Foundation/Foundation.h>
 
 #include "base/macros.h"
@@ skipping 78 matching lines @@
   // Returns the name of the notification that is sent through the notification
   // center when a resource is updated.
   virtual NSString* GetUpdateNotificationName();
 
   // Creates a new UpdatableResourceBrige.
   // The user is responsible for releasing it.
   // The UpdatableResourceBridge takes ownership of the delegate.
   // |delegate| may be nil.
   virtual id<UpdatableResourceBridge> CreateUpdatableResource(
       NSString* resource_identifier,
-      id<UpdatableResourceDelegate> delegate);
+      id<UpdatableResourceDelegate> delegate) NS_RETURNS_RETAINED;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UpdatableResourceProvider);
 };
 
 }  // namespace ios
 
 #endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_UPDATABLE_RESOURCE_PROVIDER_H_