[ios] RootCoordinator and view controller.

ios/clean/chrome/browser/ui/root/root_container_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_ROOT_ROOT_CONTAINER_VIEW_CONTROLLER_H_
+#define IOS_CLEAN_CHROME_BROWSER_UI_ROOT_ROOT_CONTAINER_VIEW_CONTROLLER_H_
+
+#import <UIKit/UIKit.h>
+
+#import "ios/clean/chrome/browser/ui/animators/zoom_transition_delegate.h"
+
+// View controller that wholly contains a content view controller.
+@interface RootContainerViewController
+    : UIViewController<ZoomTransitionDelegate>
+
+// View controller showing the main content.
+@property(nonatomic, weak) UIViewController* contentViewController;
+
+@end
+
+#endif  // IOS_CLEAN_CHROME_BROWSER_UI_ROOT_ROOT_CONTAINER_VIEW_CONTROLLER_H_