[ObjC ARC] Converts ios/chrome/browser/ui/bookmarks:bookmarks_arc to ARC.

ios/chrome/browser/ui/bookmarks/bookmark_utils_ios.h

 // Copyright (c) 2014 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_CHROME_BROWSER_UI_BOOKMARKS_BOOKMARK_UTILS_IOS_H_
 #define IOS_CHROME_BROWSER_UI_BOOKMARKS_BOOKMARK_UTILS_IOS_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
@@ skipping 167 matching lines @@
     const NodeVector& vector2);
 
 #pragma mark - Cache position in collection view.
 
 // Caches the active menu item, and the position in the collection view.
 void CachePosition(CGFloat position, BookmarkMenuItem* item);
 // Returns YES if a valid cache exists.
 // |model| must be loaded.
 // |item| and |position| are out variables, only populated if the return is YES.
 BOOL GetPositionCache(bookmarks::BookmarkModel* model,
-                      BookmarkMenuItem** item,
+                      BookmarkMenuItem* __autoreleasing* item,
                       CGFloat* position);
 // Method exists for testing.
 void ClearPositionCache();
 
 }  // namespace bookmark_utils_ios
 
 #endif  // IOS_CHROME_BROWSER_UI_BOOKMARKS_BOOKMARK_UTILS_IOS_H_