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

ios/chrome/browser/ui/ntp/new_tab_page_view.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_view.h"
 
 #include "base/logging.h"
-#include "base/mac/objc_property_releaser.h"
 #import "ios/chrome/browser/ui/ntp/new_tab_page_bar.h"
 #import "ios/chrome/browser/ui/ntp/new_tab_page_bar_item.h"
 #import "ios/chrome/browser/ui/rtl_geometry.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 
-@implementation NewTabPageView {
- @private
-  // The objects pointed to by |tabBar_| and |scrollView_| are owned as
-  // subviews already.
-  __unsafe_unretained NewTabPageBar* tabBar_;     // weak
-  __unsafe_unretained UIScrollView* scrollView_;  // weak
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
 
-  base::mac::ObjCPropertyReleaser propertyReleaser_NewTabPageView_;
-}
+@implementation NewTabPageView
 
 @synthesize scrollView = scrollView_;
 @synthesize tabBar = tabBar_;
 
 - (instancetype)initWithFrame:(CGRect)frame
                 andScrollView:(UIScrollView*)scrollView
                     andTabBar:(NewTabPageBar*)tabBar {
   self = [super initWithFrame:frame];
   if (self) {
-    propertyReleaser_NewTabPageView_.Init(self, [NewTabPageView class]);
     [self addSubview:scrollView];
     [self addSubview:tabBar];
     scrollView_ = scrollView;
     tabBar_ = tabBar;
   }
   return self;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
   NOTREACHED();
@@ skipping 86 matching lines @@
 - (CGRect)panelFrameForItemAtIndex:(NSUInteger)index {
   CGRect contentBounds = CGRectMake(0, 0, self.scrollView.contentSize.width,
                                     self.scrollView.contentSize.height);
   LayoutRect layout =
       LayoutRectForRectInBoundingRect(self.scrollView.bounds, contentBounds);
   layout.position.leading = layout.size.width * index;
   return LayoutRectGetRect(layout);
 }
 
 @end