[ObjC ARC] Converts ios/web:web to ARC.

ios/web/test/web_int_test.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_WEB_TEST_WEB_INT_TEST_H_
 #define IOS_WEB_TEST_WEB_INT_TEST_H_
 
 #import <WebKit/WebKit.h>
 
 #import "base/ios/block_types.h"
@@ skipping 53 matching lines @@
   // or NSNotFound if it is not present.
   NSInteger GetIndexOfNavigationItem(const web::NavigationItem* item);
 
   web::TestWebStateDelegate web_state_delegate_;
 
  private:
   // WebState used to load pages.
   std::unique_ptr<WebState> web_state_;
   // WebStateObserver used to wait for page loads.
   std::unique_ptr<IntTestWebStateObserver> observer_;
+
+  // The system autorelease pool is deallocated after some of the C++ objects
+  // have been destroyed in the test (e.g. WebThreadImpl). Therefore any
+  // autoreleased object will be deallocated after a lot of the expected
+  // is gone, causing DCHECKs on deallocation. Creating our own root pool
+  // application context ensures that autoreleased objects are released at the
+  // end of the test, not later after the C++ test objects are destroyed.
+  NSAutoreleasePool* rootPool_;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_TEST_WEB_INT_TEST_H_