Remove SK_SUPPORT_LEGACY_GRADIENT_DITHERING from Skia proper

src/effects/gradients/SkGradientShader.cpp

 /*
  * Copyright 2006 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 "SkGradientShaderPriv.h"
 #include "SkLinearGradient.h"
 #include "SkRadialGradient.h"
@@ skipping 272 matching lines @@
     for (int i = 0; i < n; ++i) {
         SkColor c = fOrigColors[i];
         r += SkColorGetR(c);
         g += SkColorGetG(c);
         b += SkColorGetB(c);
     }
     *lum = SkColorSetRGB(rounded_divide(r, n), rounded_divide(g, n), rounded_divide(b, n));
     return true;
 }
 
-#define SK_SUPPORT_LEGACY_GRADIENT_DITHERING
-
 SkGradientShaderBase::GradientShaderBaseContext::GradientShaderBaseContext(
         const SkGradientShaderBase& shader, const ContextRec& rec)
     : INHERITED(shader, rec)
 #ifdef SK_SUPPORT_LEGACY_GRADIENT_DITHERING
     , fDither(true)
 #else
     , fDither(rec.fPaint->isDither())
 #endif
     , fCache(shader.refCache(getPaintAlpha(), fDither))
 {
@@ skipping 901 matching lines @@
             (*stops)[i] = stop;
             stop = i < outColors - 1 ? stop + random->nextUScalar1() * (1.f - stop) : 1.f;
         }
     }
     *tm = static_cast<SkShader::TileMode>(random->nextULessThan(SkShader::kTileModeCount));
 
     return outColors;
 }
 
 #endif