Use texture strip atlas for color table filter

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 1141 matching lines @@
         fAtlas = GrTextureStripAtlas::GetAtlas(desc);
         SkASSERT(fAtlas);
 
         // We always filter the gradient table. Each table is one row of a texture, always y-clamp.
         GrTextureParams params;
         params.setFilterMode(GrTextureParams::kBilerp_FilterMode);
         params.setTileModeX(tileMode);
 
         fRow = fAtlas->lockRow(bitmap);
         if (-1 != fRow) {
-            fYCoord = fAtlas->getYOffset(fRow) + SK_ScalarHalf *
-            fAtlas->getVerticalScaleFactor();
+            fYCoord = fAtlas->getYOffset(fRow) + SK_ScalarHalf * fAtlas->getNormalizedTexelHeight();
             fCoordTransform.reset(kCoordSet, matrix, fAtlas->getTexture());
             fTextureAccess.reset(fAtlas->getTexture(), params);
         } else {
             SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(ctx, bitmap, &params));
             fCoordTransform.reset(kCoordSet, matrix, texture);
             fTextureAccess.reset(texture, params);
             fYCoord = SK_ScalarHalf;
         }
         this->addTextureAccess(&fTextureAccess);
     }
@@ skipping 61 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