Remove unused code

ios/chrome/browser/ui/content_suggestions/cells/expandable_item.h

Index: ios/chrome/browser/ui/content_suggestions/cells/expandable_item.h
diff --git a/ios/chrome/browser/ui/content_suggestions/cells/expandable_item.h b/ios/chrome/browser/ui/content_suggestions/cells/expandable_item.h
deleted file mode 100644
index 33cdaec5ed779b971971c1bf69962482f2f449a1..0000000000000000000000000000000000000000
--- a/ios/chrome/browser/ui/content_suggestions/cells/expandable_item.h
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2017 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_CELLS_EXPANDABLE_ITEM_H_
-#define IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CELLS_EXPANDABLE_ITEM_H_
-
-#import <UIKit/UIKit.h>
-
-// Protocol allowing a CollectionViewItem to be expanded.
-@protocol ExpandableItem
-
-// Whether the cells should be in expanded mode.
-@property(nonatomic) BOOL expanded;
-
-@end
-
-#endif  // IOS_CHROME_BROWSER_UI_CONTENT_SUGGESTIONS_CELLS_EXPANDABLE_ITEM_H_