Remove unused code

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

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_VIEW_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_VIEW_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
-#import "ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_expandable_item.h"
-#import "ios/chrome/browser/ui/content_suggestions/cells/content_suggestions_favicon_item.h"
 
 @class ContentSuggestion;
 @protocol ContentSuggestionsCommands;
 @protocol ContentSuggestionsDataSource;
 @protocol ContentSuggestionIdentification;
 
 // CollectionViewController to display the suggestions items.
-@interface ContentSuggestionsViewController
-    : CollectionViewController<ContentSuggestionsExpandableCellDelegate,
-                               ContentSuggestionsFaviconCellDelegate>
+@interface ContentSuggestionsViewController : CollectionViewController
 
 - (instancetype)initWithStyle:(CollectionViewControllerStyle)style
                    dataSource:(id<ContentSuggestionsDataSource>)dataSource
     NS_DESIGNATED_INITIALIZER;
 
 - (instancetype)initWithStyle:(CollectionViewControllerStyle)style
     NS_UNAVAILABLE;
 
 // Handler for the commands sent by the ContentSuggestionsViewController.
 @property(nonatomic, weak) id<ContentSuggestionsCommands>
     suggestionCommandHandler;
 // Override from superclass to have a more specific type.
 @property(nonatomic, readonly)
     CollectionViewModel<CollectionViewItem<ContentSuggestionIdentification>*>*
         collectionViewModel;
 
 // Removes the entry at |indexPath|, from the collection and its model.
 - (void)dismissEntryAtIndexPath:(NSIndexPath*)indexPath;
 // Removes the |section|.
 - (void)dismissSection:(NSInteger)section;
 // Adds the |suggestions| to the collection and its model.
 - (void)addSuggestions:(NSArray<ContentSuggestion*>*)suggestions;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CONTENT_SUGGESTIONS_VIEW_CONTROLLER_H_