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

Source/core/css/SVGCSSComputedStyleDeclaration.cpp

 /*
     Copyright (C) 2007 Eric Seidel <eric@webkit.org>
     Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
@@ skipping 65 matching lines @@
             break;
         }
     } while (paintorder >>= kPaintOrderBitwidth);
 
     return list.release();
 }
 
 PassRefPtr<SVGPaint> CSSComputedStyleDeclaration::adjustSVGPaintForCurrentColor(PassRefPtr<SVGPaint> newPaint, RenderStyle* style) const
 {
     RefPtr<SVGPaint> paint = newPaint;
-    if (paint->paintType() == SVGPaint::SVG_PAINTTYPE_CURRENTCOLOR || paint->paintType() == SVGPaint::SVG_PAINTTYPE_URI_CURRENTCOLOR) {
-        // SVG handles currentColor itself, style->color() is guaranteed not to be currentColor.
-        ASSERT(!style->color().isCurrentColor());
-        paint->setColor(style->color().color());
-    }
+    if (paint->paintType() == SVGPaint::SVG_PAINTTYPE_CURRENTCOLOR || paint->paintType() == SVGPaint::SVG_PAINTTYPE_URI_CURRENTCOLOR)
+        paint->setColor(style->color());
     return paint.release();
 }
 
 PassRefPtr<CSSValue> CSSComputedStyleDeclaration::getSVGPropertyCSSValue(CSSPropertyID propertyID, EUpdateLayout updateLayout) const
 {
     Node* node = m_node.get();
     if (!node)
         return 0;
 
     // Make sure our layout is up to date before we allow a query on these attributes.
@@ skipping 126 matching lines @@
     default:
         // If you crash here, it's because you added a css property and are not handling it
         // in either this switch statement or the one in CSSComputedStyleDelcaration::getPropertyCSSValue
         ASSERT_WITH_MESSAGE(0, "unimplemented propertyID: %d", propertyID);
     }
     LOG_ERROR("unimplemented propertyID: %d", propertyID);
     return 0;
 }
 
 }