[tab_container] Consolidate tabStrip into tab_container.

ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h

Index: ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h
diff --git a/ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h b/ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h
index 03a2bf463a0dd7d7ca0bce838f5fe7c53ca78463..f5dd0bd52bd7ed3379ce758edfe05f7452734b5b 100644
--- a/ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h
+++ b/ios/clean/chrome/browser/ui/tab/tab_container_view_controller.h
@@ -14,9 +14,8 @@
 #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>
@@ -31,6 +30,11 @@
 // 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.