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

third_party/WebKit/Source/core/editing/EditingStyleUtilities.cpp

 /*
  * Copyright (C) 2007, 2008, 2009 Apple Computer, Inc.
  * Copyright (C) 2010, 2011 Google 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
@@ skipping 18 matching lines @@
 #include "core/css/CSSColorValue.h"
 #include "core/css/CSSComputedStyleDeclaration.h"
 #include "core/css/CSSIdentifierValue.h"
 #include "core/css/StylePropertySet.h"
 #include "core/css/parser/CSSParser.h"
 #include "core/editing/EditingStyle.h"
 #include "core/editing/EditingUtilities.h"
 
 namespace blink {
 
+using namespace cssvalue;
+
 bool EditingStyleUtilities::hasAncestorVerticalAlignStyle(Node& node,
                                                           CSSValueID value) {
   for (Node& runner : NodeTraversal::inclusiveAncestorsOf(node)) {
     CSSComputedStyleDeclaration* ancestorStyle =
         CSSComputedStyleDeclaration::create(&runner);
     if (getIdentifierValue(ancestorStyle, CSSPropertyVerticalAlign) == value)
       return true;
   }
   return false;
 }
@@ skipping 140 matching lines @@
   for (Node* ancestor = node; ancestor; ancestor = ancestor->parentNode()) {
     CSSComputedStyleDeclaration* ancestorStyle =
         CSSComputedStyleDeclaration::create(ancestor);
     if (!hasTransparentBackgroundColor(ancestorStyle))
       return ancestorStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
   }
   return nullptr;
 }
 
 }  // namespace blink