[ios] Dispatcher for tab_strip and tab_grid.

ios/clean/chrome/browser/ui/tab_collection/tab_collection_view_controller.h

 // 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_CLEAN_CHROME_BROWSER_UI_TAB_COLLECTION_TAB_COLLECTION_VIEW_CONTROLLER_H_
 #define IOS_CLEAN_CHROME_BROWSER_UI_TAB_COLLECTION_TAB_COLLECTION_VIEW_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/clean/chrome/browser/ui/tab_collection/tab_collection_consumer.h"
 
-@protocol TabCommands;
 @protocol TabCollectionDataSource;
 
 // Controller for a scrolling view displaying square cells that represent
 // the user's open tabs.
 @interface TabCollectionViewController : UIViewController<TabCollectionConsumer>
 // A collection view of tabs.
 @property(nonatomic, weak, readonly) UICollectionView* tabs;
 // Data source for the tabs to be displayed.
 @property(nonatomic, weak) id<TabCollectionDataSource> dataSource;
-// Command handler to show, close, or create tabs.
-@property(nonatomic, weak) id<TabCommands> tabCommandHandler;
 @end
 
 #endif  // IOS_CLEAN_CHROME_BROWSER_UI_TAB_COLLECTION_TAB_COLLECTION_VIEW_CONTROLLER_H_