KEYGEN elements should always create LayoutBlockFlow, regardless of display type.

Source/core/html/HTMLKeygenElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 15 matching lines @@
 #include "core/html/HTMLKeygenElement.h"
 
 #include "bindings/core/v8/ExceptionStatePlaceholder.h"
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "core/html/FormDataList.h"
 #include "core/html/HTMLOptionElement.h"
 #include "core/html/HTMLSelectElement.h"
+#include "core/layout/LayoutBlockFlow.h"
 #include "platform/text/PlatformLocale.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebLocalizedString.h"
 #include "wtf/StdLibExtras.h"
 
 using namespace blink;
 
 namespace blink {
 
 using namespace HTMLNames;
 
 HTMLKeygenElement::HTMLKeygenElement(Document& document, HTMLFormElement* form)
     : HTMLFormControlElementWithState(keygenTag, document, form)
 {
 }
 
 PassRefPtrWillBeRawPtr<HTMLKeygenElement> HTMLKeygenElement::create(Document& document, HTMLFormElement* form)
 {
     RefPtrWillBeRawPtr<HTMLKeygenElement> keygen = adoptRefWillBeNoop(new HTMLKeygenElement(document, form));
     keygen->ensureClosedShadowRoot();
     return keygen.release();
 }
 
+LayoutObject* HTMLKeygenElement::createLayoutObject(const LayoutStyle& style)
+{
+    // TODO(mstensho): While it's harmful and meaningless to allow most display types on replaced
+    // content (e.g. table, table-row or flex), it would be useful to honor at least some of
+    // them. Table-cell (and maybe table-caption too), for instance. See crbug.com/335040
+    return new LayoutBlockFlow(this);
+}
+
 void HTMLKeygenElement::didAddClosedShadowRoot(ShadowRoot& root)
 {
     DEFINE_STATIC_LOCAL(AtomicString, keygenSelectPseudoId, ("-webkit-keygen-select", AtomicString::ConstructFromLiteral));
 
     Vector<String> keys;
     keys.reserveCapacity(2);
     keys.append(locale().queryString(WebLocalizedString::KeygenMenuHighGradeKeySize));
     keys.append(locale().queryString(WebLocalizedString::KeygenMenuMediumGradeKeySize));
 
     // Create a select element with one option element for each key size.
@@ skipping 51 matching lines @@
 {
     return true;
 }
 
 bool HTMLKeygenElement::supportsAutofocus() const
 {
     return true;
 }
 
 } // namespace