Generate toCSSFooValue for CSS*GradientValues

Source/core/css/resolver/StyleBuilderCustom.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
@@ skipping 1309 matching lines @@
             }
 
             if (!value->isValueList())
                 return;
 
             bool didSet = false;
             for (CSSValueListIterator i = value; i.hasMore(); i.advance()) {
                 CSSValue* item = i.value();
                 if (item->isImageGeneratorValue()) {
                     if (item->isGradientValue())
-                        state.style()->setContent(StyleGeneratedImage::create(static_cast<CSSGradientValue*>(item)->gradientWithStylesResolved(state.document().textLinkColors(), state.style()->color()).get()), didSet);
+                        state.style()->setContent(StyleGeneratedImage::create(toCSSGradientValue(item)->gradientWithStylesResolved(state.document().textLinkColors(), state.style()->color()).get()), didSet);
                     else
                         state.style()->setContent(StyleGeneratedImage::create(static_cast<CSSImageGeneratorValue*>(item)), didSet);
                     didSet = true;
                 } else if (item->isImageSetValue()) {
                     state.style()->setContent(state.elementStyleResources().setOrPendingFromValue(CSSPropertyContent, toCSSImageSetValue(item)), didSet);
                     didSet = true;
                 }
 
                 if (item->isImageValue()) {
                     state.style()->setContent(state.elementStyleResources().cachedOrPendingFromValue(CSSPropertyContent, toCSSImageValue(item)), didSet);
@@ skipping 1055 matching lines @@
         break;
     }
     case CSSPropertyEnableBackground:
         // Silently ignoring this property for now
         // http://bugs.webkit.org/show_bug.cgi?id=6022
         break;
     }
 }
 
 } // namespace WebCore