fixed <select> element isn't updated after its single option removing.

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

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * 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, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 818 matching lines @@
         }
         if (!firstEnabledOption && !option->isDisabledFormControl()) {
             firstEnabledOption = option;
             if (reason == ResetReasonSelectedOptionRemoved) {
                 // There must be no selected OPTIONs.
                 break;
             }
         }
         ++optionIndex;
     }
-    if (!lastSelectedOption && m_size <= 1 && firstEnabledOption && !firstEnabledOption->selected()) {
+    if (!lastSelectedOption && m_size <= 1 && (!firstEnabledOption || (firstEnabledOption && !firstEnabledOption->selected()))) {
         selectOption(firstEnabledOption, reason == ResetReasonSelectedOptionRemoved ? 0 : DeselectOtherOptions);
         lastSelectedOption = firstEnabledOption;
         didChange = true;
     }
     if (didChange)
         setNeedsValidityCheck();
     m_lastOnChangeOption = lastSelectedOption;
 }
 
 HTMLOptionElement* HTMLSelectElement::selectedOption() const
@@ skipping 1174 matching lines @@
 }
 
 void HTMLSelectElement::didMutateSubtree()
 {
     DCHECK(popupIsVisible());
     DCHECK(m_popup);
     m_popup->updateFromElement(PopupMenu::ByDOMChange);
 }
 
 } // namespace blink