[tab_container] Consolidate tabStrip into tab_container.

ios/clean/chrome/browser/ui/tab/tab_container_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.
 
 // ======                        New Architecture                         =====
 // =         This code is only used in the new iOS Chrome architecture.       =
 // ============================================================================
 
 #ifndef IOS_CLEAN_CHROME_BROWSER_UI_TAB_TAB_CONTAINER_VIEW_CONTROLLER_H_
 #define IOS_CLEAN_CHROME_BROWSER_UI_TAB_TAB_CONTAINER_VIEW_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #import "ios/clean/chrome/browser/ui/animators/zoom_transition_delegate.h"
 #import "ios/clean/chrome/browser/ui/presenters/menu_presentation_delegate.h"
 
-// Base class for a view controller that contains a content view (generally
-// some kind of web view, but nothing in this class assumes that) and a toolbar
-// view, each managed by their own view controllers.
+// Abstract base class for a view controller that contains several views,
+// each managed by their own view controllers.
 // Subclasses manage the specific layout of these view controllers.
 @interface TabContainerViewController
     : UIViewController<MenuPresentationDelegate, ZoomTransitionDelegate>
 
 // View controller showing the main content for the tab. If there is no
 // toolbar view controller set, the contents of this view controller will
 // fill all of the tab container's view.
 @property(nonatomic, strong) UIViewController* contentViewController;
 
 // View controller showing the toolbar for the tab. It will be of a fixed
 // height (determined internally by the tab container), but will span the
 // width of the tab.
 @property(nonatomic, strong) UIViewController* toolbarViewController;
 
+// View controller showing the tab strip. It will be of a fixed
+// height (determined internally by the tab container), but will span the
+// width of the tab.
+@property(nonatomic, strong) UIViewController* tabStripViewController;
+
 @end
 
 // Tab container which positions the toolbar at the top.
 @interface TopToolbarTabViewController : TabContainerViewController
 @end
 
 // Tab container which positions the toolbar at the bottom.
 @interface BottomToolbarTabViewController : TabContainerViewController
 @end
 
 #endif  // IOS_CLEAN_CHROME_BROWSER_UI_TAB_TAB_CONTAINER_VIEW_CONTROLLER_H_