Use isSVG*Element() helpers more in SVG code (Part 3)

Source/core/rendering/svg/ReferenceFilterBuilder.cpp

 /*
  * Copyright (C) 2013 Adobe Systems Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc.  All rights reserved.
  * Copyright (C) 2011 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.
@@ skipping 116 matching lines @@
 
     Element* filter = document->getElementById(filterOperation->fragment());
 
     if (!filter) {
         // Although we did not find the referenced filter, it might exist later
         // in the document
         document->accessSVGExtensions().addPendingResource(filterOperation->fragment(), toElement(renderer->node()));
         return nullptr;
     }
 
-    if (!filter->isSVGElement() || !filter->hasTagName(SVGNames::filterTag))
+    if (!isSVGFilterElement(*filter))
         return nullptr;
 
-    SVGFilterElement* filterElement = toSVGFilterElement(toSVGElement(filter));
+    SVGFilterElement& filterElement = toSVGFilterElement(*filter);
 
     // FIXME: Figure out what to do with SourceAlpha. Right now, we're
     // using the alpha of the original input layer, which is obviously
     // wrong. We should probably be extracting the alpha from the
     // previousEffect, but this requires some more processing.
     // This may need a spec clarification.
     RefPtr<SVGFilterBuilder> builder = SVGFilterBuilder::create(previousEffect, SourceAlpha::create(parentFilter));
 
     ColorSpace filterColorSpace = ColorSpaceDeviceRGB;
-    bool useFilterColorSpace = getSVGElementColorSpace(filterElement, filterColorSpace);
+    bool useFilterColorSpace = getSVGElementColorSpace(&filterElement, filterColorSpace);
 
-    for (SVGElement* element = Traversal<SVGElement>::firstChild(*filterElement); element; element = Traversal<SVGElement>::nextSibling(*element)) {
+    for (SVGElement* element = Traversal<SVGElement>::firstChild(filterElement); element; element = Traversal<SVGElement>::nextSibling(*element)) {
         if (!element->isFilterEffect())
             continue;
 
         SVGFilterPrimitiveStandardAttributes* effectElement = static_cast<SVGFilterPrimitiveStandardAttributes*>(element);
 
         RefPtr<FilterEffect> effect = effectElement->build(builder.get(), parentFilter);
         if (!effect)
             continue;
 
         effectElement->setStandardAttributes(effect.get());
-        effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement->primitiveUnits()->currentValue()->enumValue(), parentFilter->sourceImageRect()));
+        effect->setEffectBoundaries(SVGLengthContext::resolveRectangle<SVGFilterPrimitiveStandardAttributes>(effectElement, filterElement.primitiveUnits()->currentValue()->enumValue(), parentFilter->sourceImageRect()));
         ColorSpace colorSpace = filterColorSpace;
         if (useFilterColorSpace || getSVGElementColorSpace(effectElement, colorSpace))
             effect->setOperatingColorSpace(colorSpace);
         builder->add(AtomicString(effectElement->result()->currentValue()->value()), effect);
     }
     return builder->lastEffect();
 }
 
 } // namespace WebCore