Experiment with restricting form submission with open elements.

third_party/WebKit/Source/core/html/HTMLFormControlElement.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, 2007 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 40 matching lines @@
                                                Document& document)
     : LabelableElement(tagName, document),
       m_ancestorDisabledState(AncestorDisabledStateUnknown),
       m_dataListAncestorState(Unknown),
       m_isAutofilled(false),
       m_hasValidationMessage(false),
       m_willValidateInitialized(false),
       m_willValidate(true),
       m_isValid(true),
       m_validityIsDirty(false),
-      m_wasFocusedByMouse(false) {
+      m_wasFocusedByMouse(false),
+      m_blocksFormSubmission(false) {
   setHasCustomStyleCallbacks();
 }
 
 HTMLFormControlElement::~HTMLFormControlElement() {}
 
 DEFINE_TRACE(HTMLFormControlElement) {
   ListedElement::trace(visitor);
   LabelableElement::trace(visitor);
 }
 
@@ skipping 562 matching lines @@
     const Element& source) {
   HTMLElement::copyNonAttributePropertiesFromElement(source);
   setNeedsValidityCheck();
 }
 
 void HTMLFormControlElement::associateWith(HTMLFormElement* form) {
   associateByParser(form);
 };
 
 }  // namespace blink