Reduce number of header includes in SVG

Source/core/svg/SVGPathBlender.h

 /*
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGPathBlender_h
 #define SVGPathBlender_h
 
 #include "core/svg/SVGPathConsumer.h"
-#include "core/svg/SVGPathSource.h"
 
 namespace WebCore {
 
 enum FloatBlendMode {
     BlendHorizontal,
     BlendVertical
 };
 
+class SVGPathSource;
+
 class SVGPathBlender {
     WTF_MAKE_NONCOPYABLE(SVGPathBlender); WTF_MAKE_FAST_ALLOCATED;
 public:
     SVGPathBlender();
 
     bool addAnimatedPath(SVGPathSource*, SVGPathSource*, SVGPathConsumer*, unsigned repeatCount);
     bool blendAnimatedPath(float, SVGPathSource*, SVGPathSource*, SVGPathConsumer*);
     void cleanup();
 
 private:
@@ skipping 20 matching lines @@
     PathCoordinateMode m_fromMode;
     PathCoordinateMode m_toMode;
     float m_progress;
     unsigned m_addTypesCount;
     bool m_isInFirstHalfOfAnimation;
 };
 
 } // namespace WebCore
 
 #endif // SVGPathBlender_h