Removes unnecessary subclassing of BookmarkCollectionView.

ios/chrome/browser/ui/bookmarks/bookmark_folder_collection_view.h

-// Copyright 2014 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_BOOKMARKS_BOOKMARK_FOLDER_COLLECTION_VIEW_H_
-#define IOS_CHROME_BROWSER_UI_BOOKMARKS_BOOKMARK_FOLDER_COLLECTION_VIEW_H_
-
-#import "ios/chrome/browser/ui/bookmarks/bookmark_collection_view.h"
-
-@class BookmarkFolderCollectionView;
-
-namespace bookmarks {
-class BookmarkNode;
-}  // namespace bookmarks
-
-@protocol BookmarkFolderCollectionViewDelegate<BookmarkCollectionViewDelegate>
-// Tells the delegate that a folder was selected for navigation.
-- (void)bookmarkFolderCollectionView:(BookmarkFolderCollectionView*)view
-         selectedFolderForNavigation:(const bookmarks::BookmarkNode*)folder;
-@end
-
-// Shows all sub-folders and sub-urls of a folder node in a collection view.
-// Note: This class intentionally does not try to maintain state through a
-// folder transition. Depending on the type of animation that the designers
-// choose, we may require multiple instances of this view.
-@interface BookmarkFolderCollectionView : BookmarkCollectionView
-
-// Refreshes the entire view to reflect |folder|.
-- (void)resetFolder:(const bookmarks::BookmarkNode*)folder;
-
-// Called when something outside the view causes the promo state to change.
-- (void)promoStateChangedAnimated:(BOOL)animate;
-
-@property(nonatomic, weak) id<BookmarkFolderCollectionViewDelegate> delegate;
-@property(nonatomic, assign, readonly) const bookmarks::BookmarkNode* folder;
-
-@end
-
-#endif  // IOS_CHROME_BROWSER_UI_BOOKMARKS_BOOKMARK_FOLDER_COLLECTION_VIEW_H_