Convert main NTP panel to UIViewController.

ios/chrome/browser/ui/ntp/google_landing_controller.h

 // Copyright 2013 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_NTP_GOOGLE_LANDING_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_NTP_GOOGLE_LANDING_CONTROLLER_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
 
 #import "ios/chrome/browser/ui/ntp/new_tab_page_panel_protocol.h"
 #import "ios/chrome/browser/ui/toolbar/toolbar_owner.h"
 #import "ios/public/provider/chrome/browser/voice/logo_animation_controller.h"
 
 @protocol OmniboxFocuser;
 @class TabModel;
 @protocol UrlLoader;
 @protocol WebToolbarDelegate;
 
 namespace ios {
 class ChromeBrowserState;
 }
 
 // Google centric new tab page.
-@interface GoogleLandingController : NSObject<LogoAnimationControllerOwnerOwner,
-                                              NewTabPagePanelProtocol,
-                                              ToolbarOwner>
+@interface GoogleLandingController
+    : UIViewController<LogoAnimationControllerOwnerOwner,
+                       NewTabPagePanelProtocol,
+                       ToolbarOwner>
 
 // Initialization method.
 - (id)initWithLoader:(id<UrlLoader>)loader
           browserState:(ios::ChromeBrowserState*)browserState
                focuser:(id<OmniboxFocuser>)focuser
     webToolbarDelegate:(id<WebToolbarDelegate>)webToolbarDelegate
               tabModel:(TabModel*)tabModel;
 
 // Get the maximum number of sites shown.
 + (NSUInteger)maxSitesShown;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_NTP_GOOGLE_LANDING_CONTROLLER_H_