Add :indeterminate pseudo class support for radio button input

Source/core/html/HTMLInputElement.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, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
@@ skipping 1683 matching lines @@
         setValue(newValue);
 }
 
 String HTMLInputElement::defaultToolTip() const
 {
     return m_inputType->defaultToolTip();
 }
 
 bool HTMLInputElement::shouldAppearIndeterminate() const
 {
-    return m_inputType->supportsIndeterminateAppearance() && indeterminate();
+    return m_inputType->shouldAppearIndeterminate();
 }
 
 bool HTMLInputElement::isInRequiredRadioButtonGroup()
 {
     ASSERT(isRadioButton());
     if (RadioButtonGroupScope* scope = radioButtonGroupScope())
         return scope->isInRequiredGroup(this);
     return false;
 }
 
-HTMLInputElement* HTMLInputElement::checkedRadioButtonForGroup() const
+HTMLInputElement* HTMLInputElement::checkedRadioButtonForGroup()
 {
+    if (checked())
+        return this;

[tkent, 2014/07/15 01:31:50]

This changes a behavior.  For example,
- the input type is not radio
- this input is not in a Document tree.

Is it ok?

[keishi, 2014/07/15 03:05:30]

I think this is correct and the current behavior is a bug.

This test gives true on Chrome but false on Firefox.
http://jsbin.com/lokocepo/2/edit

Single radio buttons should form its own radio button group so I think the
correct output is false.
https://www.w3.org/Bugs/Public/show_bug.cgi?id=21820

     if (RadioButtonGroupScope* scope = radioButtonGroupScope())
         return scope->checkedButtonForGroup(name());
     return 0;
 }
 
 RadioButtonGroupScope* HTMLInputElement::radioButtonGroupScope() const
 {
     if (!isRadioButton())
         return 0;
     if (HTMLFormElement* formElement = form())
@@ skipping 152 matching lines @@
     return m_inputTypeView->customStyleForRenderer(originalStyleForRenderer());
 }
 #endif
 
 bool HTMLInputElement::shouldDispatchFormControlChangeEvent(String& oldValue, String& newValue)
 {
     return m_inputType->shouldDispatchFormControlChangeEvent(oldValue, newValue);
 }
 
 } // namespace