Remove WebToolbarDelegate from GoogleLandingDataSource.

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

 // Copyright 2014 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_NEW_TAB_PAGE_TOOLBAR_CONTROLLER_H_
 #define IOS_CHROME_BROWSER_UI_NTP_NEW_TAB_PAGE_TOOLBAR_CONTROLLER_H_
 
 #import "ios/chrome/browser/ui/toolbar/toolbar_controller.h"
 
-@protocol OmniboxFocuser;
-@protocol WebToolbarDelegate;
+@protocol GoogleLandingDataSource;
 
 // New tab page specific toolbar. The background view is hidden and the
 // navigation buttons are also hidden if there is no forward history. Does not
 // contain an omnibox but tapping in the center will focus the main toolbar's
 // omnibox.
 @interface NewTabPageToolbarController : ToolbarController
 
 // Designated initializer. The underlying ToolbarController is initialized with
 // ToolbarControllerStyleLightMode.
-- (instancetype)initWithToolbarDelegate:(id<WebToolbarDelegate>)delegate
-                                focuser:(id<OmniboxFocuser>)focuser;
+- (instancetype)initWithToolbarDataSource:
+    (id<GoogleLandingDataSource>)dataSource;
+
+// |YES| if the toolbar can show the forward arrow.
+- (void)setCanGoForward:(BOOL)canGoForward;
+
+// |YES| if the toolbar can show the back arrow.
+- (void)setCanGoBack:(BOOL)canGoBack;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_NTP_NEW_TAB_PAGE_TOOLBAR_CONTROLLER_H_