Display articles in Content Suggestions

ios/chrome/browser/ui/content_suggestions/content_suggestions_view_controller.mm

 // Copyright 2016 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/content_suggestions/content_suggestions_view_controller.h"
 
 #include "base/mac/foundation_util.h"
 #import "ios/chrome/browser/ui/collection_view/cells/MDCCollectionViewCell+Chrome.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_item.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_model.h"
@@ skipping 53 matching lines @@
 }
 
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
     didSelectItemAtIndexPath:(NSIndexPath*)indexPath {
   [super collectionView:collectionView didSelectItemAtIndexPath:indexPath];
 
   CollectionViewItem* item =
       [self.collectionViewModel itemAtIndexPath:indexPath];
-  switch (item.type) {
-    case ItemTypeStack:
-      [self.suggestionCommandHandler openReadingList];
-      break;
-    case ItemTypeArticle:
+  switch ([self.collectionUpdater contentSuggestionTypeForItem:item]) {
+    case ContentSuggestionTypeArticle:
       [self openArticle:item];
       break;
-    default:
-      break;
   }
 }
 
 #pragma mark - ContentSuggestionsExpandableCellDelegate
 
 - (void)collapseCell:(UICollectionViewCell*)cell {
   [self expand:NO cell:cell];
 }
 
 - (void)expandCell:(UICollectionViewCell*)cell {
@@ skipping 86 matching lines @@
   }
 }
 
 - (void)openArticle:(CollectionViewItem*)item {
   ContentSuggestionsArticleItem* article =
       base::mac::ObjCCastStrict<ContentSuggestionsArticleItem>(item);
   [self.suggestionCommandHandler openURL:article.articleURL];
 }
 
 @end