DCHECK style is cacheable in ComputedStyle::CopyNonInheritedFromCached.

third_party/WebKit/Source/core/css/resolver/MatchedPropertiesCache.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2013 Google Inc. 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 92 matching lines @@
                                       const MatchedPropertiesVector&);
   void Add(const ComputedStyle&,
            const ComputedStyle& parent_style,
            unsigned hash,
            const MatchedPropertiesVector&);
 
   void Clear();
   void ClearViewportDependent();
 
   static bool IsCacheable(const StyleResolverState&);
+  static bool IsStyleCacheable(const ComputedStyle&);
 
   DECLARE_TRACE();
 
  private:
   using Cache = HeapHashMap<unsigned,
                             Member<CachedMatchedProperties>,
                             DefaultHash<unsigned>::Hash,
                             HashTraits<unsigned>,
                             CachedMatchedPropertiesHashTraits>;
   Cache cache_;
 };
 
 }  // namespace blink
 
 #endif