Remove CSSParserValue usage from StyleRuleKeyframe

Source/core/css/StyleRuleKeyframe.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 StyleRuleKeyframe_h
 #define StyleRuleKeyframe_h
 
 #include "core/css/StyleRule.h"
 
 namespace blink {
 
-class CSSParserValueList;
 class MutableStylePropertySet;
 class StylePropertySet;
 
 class StyleRuleKeyframe final : public StyleRuleBase {
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(StyleRuleKeyframe);
 public:
     static PassRefPtrWillBeRawPtr<StyleRuleKeyframe> create(PassOwnPtr<Vector<double>> keys, PassRefPtrWillBeRawPtr<StylePropertySet> properties)
     {
         return adoptRefWillBeNoop(new StyleRuleKeyframe(keys, properties));
     }
 
     // Exposed to JavaScript.
     String keyText() const;
     bool setKeyText(const String&);
 
     // Used by StyleResolver.
     const Vector<double>& keys() const;
 
     const StylePropertySet& properties() const { return *m_properties; }
     MutableStylePropertySet& mutableProperties();
 
     String cssText() const;
 
     DECLARE_TRACE_AFTER_DISPATCH();
 
-    static PassOwnPtr<Vector<double>> createKeyList(CSSParserValueList*);
-
 private:
     StyleRuleKeyframe(PassOwnPtr<Vector<double>>, PassRefPtrWillBeRawPtr<StylePropertySet>);
 
     RefPtrWillBeMember<StylePropertySet> m_properties;
     Vector<double> m_keys;
 };
 
 DEFINE_STYLE_RULE_TYPE_CASTS(Keyframe);
 
 } // namespace blink
 
 #endif // StyleRuleKeyframe_h