Create headerHeightForTab in TabHeadersDelegate.

ios/chrome/browser/ui/browser_view_controller.mm

Index: ios/chrome/browser/ui/browser_view_controller.mm
diff --git a/ios/chrome/browser/ui/browser_view_controller.mm b/ios/chrome/browser/ui/browser_view_controller.mm
index dba26efc255093fb1f866eea27f75fb741f7dd64..b596ebe0a99a8be71bcadb0133878c3bc757a271 100644
--- a/ios/chrome/browser/ui/browser_view_controller.mm
+++ b/ios/chrome/browser/ui/browser_view_controller.mm
@@ -77,6 +77,7 @@
 #import "ios/chrome/browser/storekit_launcher.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_dialog_delegate.h"
+#import "ios/chrome/browser/tabs/tab_headers_delegate.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 #import "ios/chrome/browser/tabs/tab_model_observer.h"
 #import "ios/chrome/browser/tabs/tab_snapshotting_delegate.h"
@@ -310,6 +311,7 @@ NSString* const kReadingListSnackbarCategory = @"ReadingListSnackbarCategory";
                                     SnapshotOverlayProvider,
                                     StoreKitLauncher,
                                     TabDialogDelegate,
+                                    TabHeadersDelegate,
                                     TabModelObserver,
                                     TabSnapshottingDelegate,
                                     UIGestureRecognizerDelegate,
@@ -2108,6 +2110,7 @@ class BrowserBookmarkModelBridge : public bookmarks::BookmarkModelObserver {
   if (!IsIPadIdiom()) {
     tab.overscrollActionsControllerDelegate = self;
   }
+  tab.tabHeadersDelegate = self;
   tab.tabSnapshottingDelegate = self;
   // Install the proper CRWWebController delegates.
   tab.webController.nativeProvider = self;