Have Document::accessSVGExtensions() return a reference

Source/core/svg/SVGFEConvolveMatrixElement.cpp

 /*
  * Copyright (C) 2009 Dirk Schulze <krit@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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 113 matching lines @@
         m_preserveAlpha->setBaseValueAsString(value, parseError);
     else if (name == SVGNames::edgeModeAttr)
         m_edgeMode->setBaseValueAsString(value, parseError);
     else if (name == SVGNames::targetXAttr)
         m_targetX->setBaseValueAsString(value, parseError);
     else if (name == SVGNames::targetYAttr)
         m_targetY->setBaseValueAsString(value, parseError);
     else if (name == SVGNames::orderAttr) {
         m_order->setBaseValueAsString(value, parseError);
         if (parseError == NoError && (orderX()->baseValue()->value() < 1 || orderY()->baseValue()->value() < 1)) {
-            document().accessSVGExtensions()->reportWarning(
+            document().accessSVGExtensions().reportWarning(
                 "feConvolveMatrix: problem parsing order=\"" + value
                 + "\". Filtered element will not be displayed.");
         }
     } else
         ASSERT_NOT_REACHED();
 
     reportAttributeParsingError(parseError, name, value);
 }
 
 bool SVGFEConvolveMatrixElement::setFilterEffectAttribute(FilterEffect* effect, const QualifiedName& attrName)
@@ skipping 106 matching lines @@
 
     RefPtr<FilterEffect> effect = FEConvolveMatrix::create(filter,
                     IntSize(orderXValue, orderYValue), divisorValue,
                     m_bias->currentValue()->value(), IntPoint(targetXValue, targetYValue), m_edgeMode->currentValue()->enumValue(),
                     FloatPoint(kernelUnitLengthXValue, kernelUnitLengthYValue), m_preserveAlpha->currentValue()->value(), m_kernelMatrix->currentValue()->toFloatVector());
     effect->inputEffects().append(input1);
     return effect.release();
 }
 
 } // namespace WebCore