Fix renderer assert after autofill

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 7de388683f0ec641d83ef3cacaa3c95618a7c364..9eb4c4abc69546b6ecd40d53d77b0c6967b7d9af 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -3469,6 +3469,11 @@ bool Document::setFocusedElement(PassRefPtr<Element> prpNewFocusedElement, Focus
             else
                 view()->setFocus(false);
         }
+
+        // Autofill client may have modified the value of newFocusedElement, thus require
+        // a layout update here, otherwise it will assert at newFocusedElement->isFocusable().
+        // See crbug.com/251163.
+        updateLayoutIgnorePendingStylesheets();
     }
 
     if (newFocusedElement && newFocusedElement->isFocusable()) {