Update error-handling for fe*Lighting and feTurbulence

third_party/WebKit/Source/core/svg/SVGFESpecularLightingElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Oliver Hunt <oliver@nerget.com>
  *
  * 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.
  *
@@ skipping 114 matching lines @@
     primitiveAttributeChanged(attrName);
 }
 
 PassRefPtrWillBeRawPtr<FilterEffect> SVGFESpecularLightingElement::build(SVGFilterBuilder* filterBuilder, Filter* filter)
 {
     FilterEffect* input1 = filterBuilder->getEffectById(AtomicString(m_in1->currentValue()->value()));
 
     if (!input1)
         return nullptr;
 
-    SVGFELightElement* lightNode = SVGFELightElement::findLightElement(*this);
-    if (!lightNode)
-        return nullptr;
-
     LayoutObject* layoutObject = this->layoutObject();
     if (!layoutObject)
         return nullptr;
 
     ASSERT(layoutObject->style());
     Color color = layoutObject->style()->svgStyle().lightingColor();
 
-    RefPtr<LightSource> lightSource = lightNode->lightSource(filter);
-    RefPtrWillBeRawPtr<FilterEffect> effect = FESpecularLighting::create(filter, color, m_surfaceScale->currentValue()->value(), m_specularConstant->currentValue()->value(),
-        m_specularExponent->currentValue()->value(), lightSource.release());
+    const SVGFELightElement* lightNode = SVGFELightElement::findLightElement(*this);
+    RefPtr<LightSource> lightSource = lightNode ? lightNode->lightSource(filter) : nullptr;
+
+    RefPtrWillBeRawPtr<FilterEffect> effect = FESpecularLighting::create(filter,
+        color,
+        m_surfaceScale->currentValue()->value(),
+        m_specularConstant->currentValue()->value(),
+        m_specularExponent->currentValue()->value(),
+        lightSource.release());
     effect->inputEffects().append(input1);
     return effect.release();
 }
 
 } // namespace blink