Use CollectionViewTextItem instead of a cast

ios/chrome/browser/ui/settings/accounts_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/accounts_collection_view_controller.h"
 
 #import "base/ios/weak_nsobject.h"
 #import "base/mac/foundation_util.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/metrics/user_metrics.h"
@@ skipping 225 matching lines @@
       toSectionWithIdentifier:SectionIdentifierSignOut];
 }
 
 #pragma mark - Model objects
 
 - (CollectionViewItem*)header {
   CollectionViewTextItem* header = [
       [[CollectionViewTextItem alloc] initWithType:ItemTypeHeader] autorelease];
   header.text = l10n_util::GetNSString(IDS_IOS_OPTIONS_ACCOUNTS_DESCRIPTION);
   header.accessibilityIdentifier = kSettingsHeaderId;
+  header.textColor = [[MDCPalette greyPalette] tint500];
   return header;
 }
 
 - (CollectionViewItem*)accountItem:(ChromeIdentity*)identity {
   CollectionViewAccountItem* item = [[[CollectionViewAccountItem alloc]
       initWithType:ItemTypeAccount] autorelease];
   [self updateAccountItem:item withIdentity:identity];
   return item;
 }
 
@@ skipping 107 matching lines @@
       [self showGoogleActivitySettings];
       break;
     case ItemTypeSignOut:
       [self showDisconnect];
       break;
     default:
       break;
   }
 }
 
-#pragma mark - UICollectionViewDataSource
-
-- (UICollectionReusableView*)collectionView:(UICollectionView*)collectionView
-          viewForSupplementaryElementOfKind:(NSString*)kind
-                                atIndexPath:(NSIndexPath*)indexPath {
-  UICollectionReusableView* view = [super collectionView:collectionView
-                       viewForSupplementaryElementOfKind:kind
-                                             atIndexPath:indexPath];
-  MDCCollectionViewTextCell* textCell =
-      base::mac::ObjCCast<MDCCollectionViewTextCell>(view);
-  if (textCell) {
-    textCell.textLabel.textColor = [[MDCPalette greyPalette] tint500];
-  }
-  return view;
-}
-
 #pragma mark - MDCCollectionViewStylingDelegate
 
 - (CGFloat)collectionView:(UICollectionView*)collectionView
     cellHeightAtIndexPath:(NSIndexPath*)indexPath {
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
   if (item.type == ItemTypeGoogleActivityControls ||
       item.type == ItemTypeSync) {
     return [MDCCollectionViewCell
         cr_preferredHeightForWidth:CGRectGetWidth(collectionView.bounds)
@@ skipping 268 matching lines @@
       [self.collectionViewModel indexPathForItem:item
                          inSectionWithIdentifier:SectionIdentifierAccounts];
   [self.collectionView reloadItemsAtIndexPaths:@[ indexPath ]];
 }
 
 - (void)onChromeIdentityServiceWillBeDestroyed {
   _identityServiceObserver.reset();
 }
 
 @end