Create headerHeightForTab in TabHeadersDelegate.

ios/chrome/browser/tabs/tab.h

 // Copyright 2012 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_TABS_TAB_H_
 #define IOS_CHROME_BROWSER_TABS_TAB_H_
 
 #import <UIKit/UIKit.h>
 
 #include <memory>
@@ skipping 22 matching lines @@
 @protocol OverscrollActionsControllerDelegate;
 @protocol PassKitDialogProvider;
 @class PasswordController;
 @class SnapshotManager;
 @protocol SnapshotOverlayProvider;
 @protocol StoreKitLauncher;
 @class FormSuggestionController;
 @protocol TabDelegate;
 @protocol TabDialogDelegate;
 @class Tab;
+@protocol TabHeadersDelegate;
 @class TabModel;
 @protocol TabSnapshottingDelegate;
 @class TranslateControllerImplIOS;
 @class WebControllerSnapshotHelper;
 
 namespace infobars {
 class InfoBarManager;
 }
 
 namespace ios {
@@ skipping 74 matching lines @@
 
 // webStateImpl is deprecated: use webState instead.
 @property(nonatomic, readonly) web::WebStateImpl* webStateImpl;
 @property(nonatomic, readonly) web::WebState* webState;
 
 @property(nonatomic, readonly) CRWWebController* webController;
 @property(nonatomic, readonly) PasswordController* passwordController;
 @property(nonatomic, readonly) BOOL canGoBack;
 @property(nonatomic, readonly) BOOL canGoForward;
 @property(nonatomic, assign) id<TabDelegate> delegate;
+@property(nonatomic, assign) id<TabHeadersDelegate> tabHeadersDelegate;
 @property(nonatomic, assign) id<TabSnapshottingDelegate>
     tabSnapshottingDelegate;
 @property(nonatomic, readonly) BOOL useDesktopUserAgent;
 @property(nonatomic, assign) id<StoreKitLauncher> storeKitLauncher;
 @property(nonatomic, assign) id<FullScreenControllerDelegate>
     fullScreenControllerDelegate;
 @property(nonatomic, readonly)
     OverscrollActionsController* overscrollActionsController;
 @property(nonatomic, assign) id<OverscrollActionsControllerDelegate>
     overscrollActionsControllerDelegate;
@@ skipping 198 matching lines @@
 
 // Called when this tab is hidden.
 - (void)wasHidden;
 
 // Evaluates U2F result.
 - (void)evaluateU2FResultFromURL:(const GURL&)url;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_TABS_TAB_H_