Centralize TextStream functions to remove RenderTreeAsText dependency of the filters

Source/core/platform/graphics/filters/FEDisplacementMap.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 10 matching lines @@
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "config.h"
 
 #include "core/platform/graphics/filters/FEDisplacementMap.h"
 
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/filters/Filter.h"
-#include "core/rendering/RenderTreeAsText.h"
 #include "platform/text/TextStream.h"
 #include "wtf/Uint8ClampedArray.h"
 
 #include "SkBitmapSource.h"
 #include "SkDisplacementMapEffect.h"
 #include "core/platform/graphics/filters/SkiaImageFilterBuilder.h"
 #include "core/platform/graphics/skia/NativeImageSkia.h"
 
 namespace WebCore {
 
@@ skipping 213 matching lines @@
     FilterEffect::externalRepresentation(ts);
     ts << " scale=\"" << m_scale << "\" "
        << "xChannelSelector=\"" << m_xChannelSelector << "\" "
        << "yChannelSelector=\"" << m_yChannelSelector << "\"]\n";
     inputEffect(0)->externalRepresentation(ts, indent + 1);
     inputEffect(1)->externalRepresentation(ts, indent + 1);
     return ts;
 }
 
 } // namespace WebCore