Adds accessoryType property to CollectionViewItem

ios/chrome/browser/ui/collection_view/cells/collection_view_item.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_COLLECTION_VIEW_CELLS_COLLECTION_VIEW_ITEM_H_
 #define IOS_CHROME_BROWSER_UI_COLLECTION_VIEW_CELLS_COLLECTION_VIEW_ITEM_H_
 
 #import <UIKit/UIKit.h>
 
-@class MDCCollectionViewCell;
+#import "ios/third_party/material_components_ios/src/components/CollectionCells/src/MaterialCollectionCells.h"
 
 // CollectionViewItem holds the model data for a given collection view item.
 @interface CollectionViewItem : NSObject<UIAccessibilityIdentification>
 
+// The accessory type for the cell.
+@property(nonatomic) MDCCollectionViewCellAccessoryType accessoryType;
+
 // A client-defined value. It should be unique among items of a given collection
 // view model.
 @property(nonatomic, readonly, assign) NSInteger type;
 
 // The cell class to use in conjunction with this item. Must be a subclass of
 // MDCCollectionViewCell. The default is MDCCollectionViewCell.
 @property(nonatomic, assign) Class cellClass;
 
 - (instancetype)initWithType:(NSInteger)type NS_DESIGNATED_INITIALIZER;
 - (instancetype)init NS_UNAVAILABLE;
 
 // Configures the given cell with the item's information. Override this method
 // to specialize. At this level, only accessibility properties are ported from
 // the item to the cell.
 // The cell's class must match cellClass for the given instance.
 - (void)configureCell:(MDCCollectionViewCell*)cell NS_REQUIRES_SUPER;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_COLLECTION_VIEW_CELLS_COLLECTION_VIEW_ITEM_H_