Introduce GrColorSpaceXform, for gamut conversion on textures

src/effects/SkXfermodeImageFilter.cpp

 /*
  * Copyright 2013 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkXfermodeImageFilter.h"
 
 #include "SkCanvas.h"
@@ skipping 170 matching lines @@
     GrPaint paint;
     // SRGBTODO: AllowSRGBInputs?
     sk_sp<GrFragmentProcessor> bgFP;
 
     if (backgroundTex) {
         SkMatrix backgroundMatrix;
         backgroundMatrix.setIDiv(backgroundTex->width(), backgroundTex->height());
         backgroundMatrix.preTranslate(SkIntToScalar(-backgroundOffset.fX),
                                       SkIntToScalar(-backgroundOffset.fY));
         bgFP = GrTextureDomainEffect::Make(
-                            backgroundTex.get(), backgroundMatrix,
+                            backgroundTex.get(), nullptr, backgroundMatrix,
                             GrTextureDomain::MakeTexelDomain(backgroundTex.get(),
                                                              background->subset()),
                             GrTextureDomain::kDecal_Mode,
                             GrTextureParams::kNone_FilterMode);
     } else {
         bgFP = GrConstColorProcessor::Make(GrColor_TRANSPARENT_BLACK,
                                              GrConstColorProcessor::kIgnore_InputMode);
     }
 
     if (foregroundTex) {
         SkMatrix foregroundMatrix;
         foregroundMatrix.setIDiv(foregroundTex->width(), foregroundTex->height());
         foregroundMatrix.preTranslate(SkIntToScalar(-foregroundOffset.fX),
                                       SkIntToScalar(-foregroundOffset.fY));
 
         sk_sp<GrFragmentProcessor> foregroundFP;
 
         foregroundFP = GrTextureDomainEffect::Make(
-                            foregroundTex.get(), foregroundMatrix,
+                            foregroundTex.get(), nullptr, foregroundMatrix,
                             GrTextureDomain::MakeTexelDomain(foregroundTex.get(), 
                                                              foreground->subset()),
                             GrTextureDomain::kDecal_Mode,
                             GrTextureParams::kNone_FilterMode);
 
         paint.addColorFragmentProcessor(std::move(foregroundFP));
 
         // A null fMode is interpreted to mean kSrcOver_Mode (to match raster).
         SkAutoTUnref<SkXfermode> mode(SkSafeRef(fMode.get()));
         if (!mode) {
@@ skipping 30 matching lines @@
     SkMatrix matrix;
     matrix.setTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
     drawContext->drawRect(GrNoClip(), paint, matrix, SkRect::Make(bounds));
 
     return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(bounds.width(), bounds.height()),
                                        kNeedNewImageUniqueID_SpecialImage,
                                        drawContext->asTexture());
 }
 
 #endif