Make CSSValuePool thread local to ensure correct parsing in colors on workers

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

 /*
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 44 matching lines @@
     RawPtr<CSSCustomIdentValue> createIdentifierValue(CSSPropertyID identifier);
     RawPtr<CSSColorValue> createColorValue(RGBA32 rgbValue);
     RawPtr<CSSPrimitiveValue> createValue(double value, CSSPrimitiveValue::UnitType);
     RawPtr<CSSPrimitiveValue> createValue(const Length& value, const ComputedStyle&);
     RawPtr<CSSPrimitiveValue> createValue(const Length& value, float zoom) { return CSSPrimitiveValue::create(value, zoom); }
     template<typename T> static RawPtr<CSSPrimitiveValue> createValue(T value) { return CSSPrimitiveValue::create(value); }
 
     DECLARE_TRACE();
 
 private:
+    friend class ExecutionContext;
     CSSValuePool();
 
     Member<CSSInheritedValue> m_inheritedValue;
     Member<CSSInitialValue> m_implicitInitialValue;
     Member<CSSInitialValue> m_explicitInitialValue;
     Member<CSSUnsetValue> m_unsetValue;
 
     HeapVector<Member<CSSPrimitiveValue>, numCSSValueKeywords> m_identifierValueCache;
 
     using ColorValueCache = HeapHashMap<unsigned, Member<CSSColorValue>>;
@@ skipping 15 matching lines @@
     FontFamilyValueCache m_fontFamilyValueCache;
 
     friend CORE_EXPORT CSSValuePool& cssValuePool();
 };
 
 CORE_EXPORT CSSValuePool& cssValuePool();
 
 } // namespace blink
 
 #endif