Implement all shorthand property.

Source/core/css/StylePropertySerializer.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.
  * Copyright (C) 2013 Intel Corporation. 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.
@@ skipping 49 matching lines @@
 }
 
 String StylePropertySerializer::asText() const
 {
     StringBuilder result;
 
     BitArray<numCSSProperties> shorthandPropertyUsed;
     BitArray<numCSSProperties> shorthandPropertyAppeared;
 
     unsigned size = m_propertySet.propertyCount();
+
+    // FIXME: need to support "unset".
+    // 'all' property: http://dev.w3.org/csswg/css-cascade/#all-shorthand
+    // 'unset" value: http://dev.w3.org/csswg/css-cascade/#unset
+    if (size == allShorthand().length() && shorthandHasOnlyInitialOrInheritedValue(allShorthand())) {
+        StylePropertySet::PropertyReference property = m_propertySet.propertyAt(0);
+        return getPropertyText(CSSPropertyAll, getCommonValue(allShorthand()), property.isImportant(), false);
+    }
+
     unsigned numDecls = 0;
     for (unsigned n = 0; n < size; ++n) {
         StylePropertySet::PropertyReference property = m_propertySet.propertyAt(n);
         CSSPropertyID propertyID = property.id();
         // Only enabled or internal properties should be part of the style.
         ASSERT(RuntimeCSSEnabled::isCSSPropertyEnabled(propertyID) || isInternalProperty(propertyID));
         CSSPropertyID shorthandPropertyID = CSSPropertyInvalid;
         CSSPropertyID borderFallbackShorthandProperty = CSSPropertyInvalid;
         String value;
 
@@ skipping 762 matching lines @@
             isInitialValue = false;
         if (!value->isInheritedValue())
             isInheritedValue = false;
         if (isImportant != m_propertySet.propertyIsImportant(shorthand.properties()[i]))
             return false;
     }
     return isInitialValue || isInheritedValue;
 }
 
 }