Revert r154797: "Move isValid/isCurrentColor from Color to StyleColor"

Source/core/accessibility/AccessibilityNodeObject.cpp

 /*
 * Copyright (C) 2012, 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 915 matching lines @@
 
     if (!node() || !node()->hasTagName(inputTag))
         return;
 
     HTMLInputElement* input = toHTMLInputElement(node());
     const AtomicString& type = input->getAttribute(typeAttr);
     if (!equalIgnoringCase(type, "color"))
         return;
 
     // HTMLInputElement::value always returns a string parseable by Color().
-    StyleColor color(input->value());
+    Color color(input->value());
     r = color.red();
     g = color.green();
     b = color.blue();
 }
 
 String AccessibilityNodeObject::valueDescription() const
 {
     if (!supportsRangeValue())
         return String();
 
@@ skipping 850 matching lines @@
         useTextUnderElement = true;
 
     if (useTextUnderElement) {
         String text = textUnderElement();
         if (!text.isEmpty())
             textOrder.append(AccessibilityText(text, ChildrenText));
     }
 }
 
 } // namespace WebCore