Reland of "Cleaned up old navigation code that did not use pending navigation item."

ios/web/interstitials/web_interstitial_impl.mm

Index: ios/web/interstitials/web_interstitial_impl.mm
diff --git a/ios/web/interstitials/web_interstitial_impl.mm b/ios/web/interstitials/web_interstitial_impl.mm
index 30698e685af337157ee9d24329ae96206422b708..1a9febb41a5510d446a02e7e28c507fae7d87804 100644
--- a/ios/web/interstitials/web_interstitial_impl.mm
+++ b/ios/web/interstitials/web_interstitial_impl.mm
@@ -84,19 +84,12 @@ void WebInterstitialImpl::DontProceed() {
 
   // Clear the pending entry, since that's the page that's not being
   // proceeded to.
-  NavigationManager* nav_manager = GetWebStateImpl()->GetNavigationManager();
-  nav_manager->DiscardNonCommittedItems();
+  GetWebStateImpl()->GetNavigationManager()->DiscardNonCommittedItems();
 
   Hide();
 
   GetDelegate()->OnDontProceed();
 
-  NSUserDefaults* user_defaults = [NSUserDefaults standardUserDefaults];
-  if (![user_defaults boolForKey:@"PendingIndexNavigationDisabled"]) {
-    // Reload last committed entry.
-    nav_manager->Reload(ReloadType::NORMAL, true /* check_for_repost */);
-  }
-
   delete this;
 }