Drop some dead code from FilterEffect

Source/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 75 matching lines @@
 }
 
 bool FEDisplacementMap::setScale(float scale)
 {
     if (m_scale == scale)
         return false;
     m_scale = scale;
     return true;
 }
 
-void FEDisplacementMap::setResultColorSpace(ColorSpace)
-{
-    // Spec: The 'color-interpolation-filters' property only applies to the 'in2' source image
-    // and does not apply to the 'in' source image. The 'in' source image must remain in its

[Stephen White, 2015/04/20 15:35:43]

This points out that there may be a bug in
FEDisplacementMap::createImageFilter(). Likely it should be passing
inputEffect(0)->operatingColorspace() to the first call to builder->builder(),
not operatingColorSpace().

If so, we're probably missing test coverage here.

[fs, 2015/04/20 15:59:29]

Yes, I noticed this discrepancy too... The commit that added this code [1], did
add tests too though, so I guess we need to check why that didn't notice it...

[1]
https://chromium.googlesource.com/chromium/blink/+/7d24fcc63dadc6a9e16159615e...

-    // current color space.
-    // The result is in that smae color space because it is a displacement of the 'in' image.
-    FilterEffect::setResultColorSpace(inputEffect(0)->resultColorSpace());
-}
-
 static SkDisplacementMapEffect::ChannelSelectorType toSkiaMode(ChannelSelectorType type)
 {
     switch (type) {
     case CHANNEL_R:
         return SkDisplacementMapEffect::kR_ChannelSelectorType;
     case CHANNEL_G:
         return SkDisplacementMapEffect::kG_ChannelSelectorType;
     case CHANNEL_B:
         return SkDisplacementMapEffect::kB_ChannelSelectorType;
     case CHANNEL_A:
@@ skipping 63 matching lines @@
     rect = mapPaintRect(rect, false);
     rect = inputEffect(0)->determineAbsolutePaintRect(rect);
     rect = mapPaintRect(rect, true);
     rect.intersect(requestedRect);
 
     addAbsolutePaintRect(rect);
     return rect;
 }
 
 } // namespace blink