Add CSS Transition support to registered custom properties

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

 // Copyright 2014 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 CSSPropertyEquality_h
 #define CSSPropertyEquality_h
 
 #include "core/CSSPropertyNames.h"
 #include "wtf/Allocator.h"
+#include "wtf/text/AtomicString.h"
 
 namespace blink {
 
 class ComputedStyle;
 
 class CSSPropertyEquality {
   STATIC_ONLY(CSSPropertyEquality);
 
  public:
   static bool propertiesEqual(CSSPropertyID,
                               const ComputedStyle&,
                               const ComputedStyle&);
+
+  static bool registeredCustomPropertiesEqual(
+      const WTF::AtomicString& propertyName,
+      const ComputedStyle&,
+      const ComputedStyle&);
 };
 
 }  // namespace blink
 
 #endif  // CSSPropertyEquality_h