Centralize TextStream functions to remove RenderTreeAsText dependency of the filters

Source/core/platform/graphics/filters/FEGaussianBlur.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) 2010 Igalia, S.L.
  * 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
@@ skipping 13 matching lines @@
  */
 
 #include "config.h"
 
 #include "core/platform/graphics/filters/FEGaussianBlur.h"
 
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/cpu/arm/filters/FEGaussianBlurNEON.h"
 #include "core/platform/graphics/filters/Filter.h"
 #include "core/platform/graphics/filters/SkiaImageFilterBuilder.h"
-#include "core/rendering/RenderTreeAsText.h"
 #include "platform/text/TextStream.h"
 #include "wtf/MathExtras.h"
 #include "wtf/ParallelJobs.h"
 #include "wtf/Uint8ClampedArray.h"
 
 #include "SkBlurImageFilter.h"
 
 using namespace std;
 
 static inline float gaussianKernelFactor()
@@ skipping 311 matching lines @@
     return ts;
 }
 
 float FEGaussianBlur::calculateStdDeviation(float radius)
 {
     // Blur radius represents 2/3 times the kernel size, the dest pixel is half of the radius applied 3 times
     return max((radius * 2 / 3.f - 0.5f) / gaussianKernelFactor(), 0.f);
 }
 
 } // namespace WebCore