[ObjC ARC] Converts ios/chrome/browser/ui/ntp:ntp_internal to ARC.

ios/chrome/browser/ui/ntp/new_tab_page_bar_item.mm

 // Copyright 2012 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.
 
 #import "ios/chrome/browser/ui/ntp/new_tab_page_bar_item.h"
 
-#include "base/mac/objc_property_releaser.h"
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
 
-@implementation NewTabPageBarItem {
-  // Title of the button.
-  NSString* title_;
-  // A numeric identifier.
-  NSUInteger identifier_;
-  // Tabbar image.
-  UIImage* image_;
-  // New tab page view.
-  __unsafe_unretained UIView* view_;  // weak
-  base::mac::ObjCPropertyReleaser propertyReleaser_NewTabPageBarItem_;
-}
-
+@implementation NewTabPageBarItem
 @synthesize title = title_;
 @synthesize identifier = identifier_;
 @synthesize image = image_;
 @synthesize view = view_;
 
 + (NewTabPageBarItem*)newTabPageBarItemWithTitle:(NSString*)title
                                       identifier:(NSUInteger)identifier
                                            image:(UIImage*)image {
-  NewTabPageBarItem* item = [[[NewTabPageBarItem alloc] init] autorelease];
+  NewTabPageBarItem* item = [[NewTabPageBarItem alloc] init];
   if (item) {
     item.title = title;
     item.identifier = identifier;
     item.image = image;
   }
   return item;
 }
 
-- (id)init {
-  self = [super init];
-  if (self) {
-    propertyReleaser_NewTabPageBarItem_.Init(self, [NewTabPageBarItem class]);
-  }
-  return self;
-}
-
 @end