Don't create m_style for option element in display:none subtree.

third_party/WebKit/Source/core/html/HTMLOptionElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Motorola Mobility, Inc.  All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 76 matching lines @@
 
     return element;
 }
 
 void HTMLOptionElement::attach(const AttachContext& context)
 {
     AttachContext optionContext(context);
     if (context.resolvedStyle) {
         ASSERT(!m_style || m_style == context.resolvedStyle);
         m_style = context.resolvedStyle;
-    } else {
+    } else if (parentComputedStyle()) {
         updateNonComputedStyle();
         optionContext.resolvedStyle = m_style.get();
     }
     HTMLElement::attach(optionContext);
 }
 
 void HTMLOptionElement::detach(const AttachContext& context)
 {
     m_style.clear();
     HTMLElement::detach(context);
@@ skipping 364 matching lines @@
         ASSERT(parent);
         if (isHTMLOptGroupElement(*parent)) {
             const ComputedStyle* parentStyle = parent->computedStyle() ? parent->computedStyle() : parent->ensureComputedStyle();
             return !parentStyle || parentStyle->display() == NONE;
         }
     }
     return m_style->display() == NONE;
 }
 
 } // namespace blink