Clear mutable inline style when it is empty.

Source/core/css/PropertySetCSSStyleDeclaration.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Research In Motion Limited. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 #include "core/css/PropertySetCSSStyleDeclaration.h"
 
 #include "HTMLNames.h"
 #include "RuntimeEnabledFeatures.h"
 #include "bindings/v8/ExceptionState.h"
 #include "core/css/CSSParser.h"
 #include "core/css/CSSStyleSheet.h"
+#include "core/css/InlineVariablesIterator.h"
 #include "core/css/StylePropertySet.h"
+#include "core/css/VariablesIterator.h"
 #include "core/dom/Element.h"
 #include "core/dom/MutationObserverInterestGroup.h"
 #include "core/dom/MutationRecord.h"
 #include "core/inspector/InspectorInstrumentation.h"
 
 using namespace std;
 
 namespace WebCore {
 
 namespace {
@@ skipping 378 matching lines @@
 void InlineCSSStyleDeclaration::didMutate(MutationType type)
 {
     if (type == NoChanges)
         return;
 
     m_cssomCSSValueClones.clear();
 
     if (!m_parentElement)
         return;
 
+    m_parentElement->clearMutableInlineStyleIfEmpty();
     m_parentElement->setNeedsStyleRecalc(LocalStyleChange);
     m_parentElement->invalidateStyleAttribute();
     StyleAttributeMutationScope(this).didInvalidateStyleAttr();
 }
 
 CSSStyleSheet* InlineCSSStyleDeclaration::parentStyleSheet() const
 {
     return m_parentElement ? m_parentElement->document().elementSheet() : 0;
 }
 
 void InlineCSSStyleDeclaration::ref()
 {
     m_parentElement->ref();
 }
 
 void InlineCSSStyleDeclaration::deref()
 {
     m_parentElement->deref();
 }
 
+PassRefPtr<CSSVariablesIterator> InlineCSSStyleDeclaration::variablesIterator() const
+{
+    return InlineVariablesIterator::create(m_parentElement);
+}
+
 
 } // namespace WebCore