[ObjC ARC] Converts ios/chrome/browser/ui/settings:settings_arc_transition to ARC.

ios/chrome/browser/ui/settings/do_not_track_collection_view_controller.mm

 // 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.
 
 #import "ios/chrome/browser/ui/settings/do_not_track_collection_view_controller.h"
 
 #include "base/mac/foundation_util.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/prefs/pref_member.h"
 #include "ios/chrome/browser/application_context.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #include "ios/chrome/browser/pref_names.h"
 #import "ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_footer_item.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_switch_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
 #include "ios/chrome/grit/ios_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 typedef NS_ENUM(NSInteger, SectionIdentifier) {
   SectionIdentifierSwitch = kSectionIdentifierEnumZero,
   SectionIdentifierFooter,
 };
 
 typedef NS_ENUM(NSInteger, ItemType) {
   ItemTypeSwitch = kItemTypeEnumZero,
   ItemTypeFooter,
@@ skipping 35 matching lines @@
   [model addSectionWithIdentifier:SectionIdentifierSwitch];
   [model addItem:[self switchItem]
       toSectionWithIdentifier:SectionIdentifierSwitch];
 
   [model addSectionWithIdentifier:SectionIdentifierFooter];
   [model addItem:[self footerItem]
       toSectionWithIdentifier:SectionIdentifierFooter];
 }
 
 - (CollectionViewItem*)switchItem {
-  CollectionViewSwitchItem* item = [[[CollectionViewSwitchItem alloc]
-      initWithType:ItemTypeSwitch] autorelease];
+  CollectionViewSwitchItem* item =
+      [[CollectionViewSwitchItem alloc] initWithType:ItemTypeSwitch];
   item.text = l10n_util::GetNSString(IDS_IOS_OPTIONS_DO_NOT_TRACK_MOBILE);
   item.on = _doNotTrackEnabled.GetValue();
   return item;
 }
 
 - (CollectionViewItem*)footerItem {
   NSString* footerText = l10n_util::GetNSString(
       IDS_IOS_OPTIONS_ENABLE_DO_NOT_TRACK_BUBBLE_TEXT_MOBILE);
   GURL learnMoreURL = google_util::AppendGoogleLocaleParam(
       GURL(kDoNotTrackLearnMoreURL),
       GetApplicationContext()->GetApplicationLocale());
 
-  CollectionViewFooterItem* item = [[[CollectionViewFooterItem alloc]
-      initWithType:ItemTypeFooter] autorelease];
+  CollectionViewFooterItem* item =
+      [[CollectionViewFooterItem alloc] initWithType:ItemTypeFooter];
   item.text = footerText;
   item.linkURL = learnMoreURL;
   item.linkDelegate = self;
   return item;
 }
 
 #pragma mark - Actions
 
 - (void)switchToggled:(id)sender {
   NSIndexPath* switchPath =
@@ skipping 85 matching lines @@
   switch (type) {
     case ItemTypeFooter:
     case ItemTypeSwitch:
       return YES;
     default:
       return NO;
   }
 }
 
 @end