Introduce the nested namespace ::blink::cssvalue, start with CSSColorValue.

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

 /*
  * 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 12 matching lines @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/css/CSSValuePool.h"
 
 #include "platform/heap/Handle.h"
 #include "wtf/Threading.h"
 
 namespace blink {
 
+using namespace cssvalue;
+
 CSSValuePool& cssValuePool() {
   DEFINE_THREAD_SAFE_STATIC_LOCAL(
       ThreadSpecific<Persistent<CSSValuePool>>, threadSpecificPool,
       new ThreadSpecific<Persistent<CSSValuePool>>());
   Persistent<CSSValuePool>& poolHandle = *threadSpecificPool;
   if (!poolHandle) {
     poolHandle = new CSSValuePool;
     poolHandle.registerAsStaticReference();
   }
   return *poolHandle;
@@ skipping 22 matching lines @@
   visitor->trace(m_identifierValueCache);
   visitor->trace(m_pixelValueCache);
   visitor->trace(m_percentValueCache);
   visitor->trace(m_numberValueCache);
   visitor->trace(m_colorValueCache);
   visitor->trace(m_fontFaceValueCache);
   visitor->trace(m_fontFamilyValueCache);
 }
 
 }  // namespace blink