Disallow WKBackForwardListItem navigations for pushState pages.

ios/web/web_state/ui/crw_web_controller.mm

Index: ios/web/web_state/ui/crw_web_controller.mm
diff --git a/ios/web/web_state/ui/crw_web_controller.mm b/ios/web/web_state/ui/crw_web_controller.mm
index ac54fae6cb1165cbe32452f382ac5e5a74d5c55b..b00480f8839552a20b2481b17fdedcf05b3c70c7 100644
--- a/ios/web/web_state/ui/crw_web_controller.mm
+++ b/ios/web/web_state/ui/crw_web_controller.mm
@@ -1853,6 +1853,15 @@ - (void)updateCurrentBackForwardListItemHolder {
   // page, and should not be associated.
   if (_webUIManager)
     return;
+  // The WKWebViewConfiguration's |userScripts| are not injected when navigating
+  // via BFLI to a page created using window.history.pushState.  This means that
+  // calling window.history navigation functions will invoke WKWebView's
+  // non-overridden implementations, causing a mismatch between the
+  // WKBackForwardList and NavigationManager.
+  web::NavigationItemImpl* currentItem =
+      [self currentSessionEntry].navigationItemImpl;
+  if (currentItem->IsCreatedFromPushState())
+    return;
 
   web::WKBackForwardListItemHolder* holder =
       [self currentBackForwardListItemHolder];