[ios] Removed -[CRWSessionController goDelta:].

ios/web/web_state/ui/crw_web_controller.mm

 // 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.
 
 #import "ios/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 2360 matching lines @@
   }
 
   [self restoreStateFromHistory];
   _webStateImpl->OnPageLoaded(currentURL, loadSuccess);
   _webStateImpl->SetIsLoading(false);
   // Inform the embedder the load completed.
   [_delegate webDidFinishWithURL:currentURL loadSuccess:loadSuccess];
 }
 
 - (void)goDelta:(int)delta {
+  if (_isBeingDestroyed)
+    return;
+
   if (delta == 0) {
     [self reload];
-  } else if ([self.sessionController canGoDelta:delta]) {
+  } else if (_webStateImpl->GetNavigationManager()->CanGoToOffset(delta)) {
     [self goToItemAtIndex:[self.sessionController indexOfEntryForDelta:delta]];
   }
 }
 
 - (void)finishHistoryNavigationFromEntry:(CRWSessionEntry*)fromEntry {
   [_delegate webWillFinishHistoryNavigationFromEntry:fromEntry];
 
   // Only load the new URL if it has a different document than |fromEntry| to
   // prevent extra page loads from NavigationItems created by hash changes or
   // calls to window.history.pushState().
@@ skipping 3333 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end