Split out CSSPrimitiveValue's PropertyID into CSSCustomIdentValue

third_party/WebKit/Source/core/css/CSSCustomIdentValue.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CSSCustomIdentValue_h
 #define CSSCustomIdentValue_h
 
+#include "core/CSSPropertyNames.h"
 #include "core/css/CSSValue.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace blink {
 
 class CSSCustomIdentValue : public CSSValue {
 public:
     static PassRefPtrWillBeRawPtr<CSSCustomIdentValue> create(const String& str)
     {
         return adoptRefWillBeNoop(new CSSCustomIdentValue(str));
     }
 
-    String value() const { return m_string; }
+    // TODO(sashab, timloh): Remove this and lazily parse the CSSPropertyID in isKnownPropertyID().
+    static PassRefPtrWillBeRawPtr<CSSCustomIdentValue> create(CSSPropertyID id)
+    {
+        return adoptRefWillBeNoop(new CSSCustomIdentValue(id));
+    }
+
+    String value() const { ASSERT(!isKnownPropertyID()); return m_string; }
+    bool isKnownPropertyID() const { return m_propertyId != CSSPropertyInvalid; }
+    CSSPropertyID valueAsPropertyID() const { ASSERT(isKnownPropertyID()); return m_propertyId; }
 
     String customCSSText() const;
 
     bool equals(const CSSCustomIdentValue& other) const
     {
-        return m_string == other.m_string;
+        return isKnownPropertyID() ? m_propertyId == other.m_propertyId : m_string == other.m_string;
     }
 
     DECLARE_TRACE_AFTER_DISPATCH();
 
 private:
     CSSCustomIdentValue(const String&);
+    CSSCustomIdentValue(CSSPropertyID);
 
+    // TODO(sashab): Change this to an AtomicString.
     String m_string;
+    CSSPropertyID m_propertyId;
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSCustomIdentValue, isCustomIdentValue());
 
 } // namespace blink
 
 #endif // CSSCustomIdentValue_h