Use threshold of 1 texture coord value per pixel w/ nearest neighbor.

src/effects/gradients/SkGradientShader.cpp

Index: src/effects/gradients/SkGradientShader.cpp
diff --git a/src/effects/gradients/SkGradientShader.cpp b/src/effects/gradients/SkGradientShader.cpp
index 815a81fe7c24a2ac545999aeb3bb084a7fc36cc0..dce079e9aebf29d564574414e11d0b36f736ee25 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -1106,11 +1106,11 @@ GrGradientEffect::GrGradientEffect(GrContext* ctx,
         fRow = fAtlas->lockRow(bitmap);
         if (-1 != fRow) {
             fYCoord = fAtlas->getYOffset(fRow) + SK_ScalarHalf * fAtlas->getNormalizedTexelHeight();
-            fCoordTransform.reset(kCoordSet, matrix, fAtlas->getTexture());
+            fCoordTransform.reset(kCoordSet, matrix, fAtlas->getTexture(), params.filterMode());
             fTextureAccess.reset(fAtlas->getTexture(), params);
         } else {
             SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(ctx, bitmap, &params));
-            fCoordTransform.reset(kCoordSet, matrix, texture);
+            fCoordTransform.reset(kCoordSet, matrix, texture, params.filterMode());
             fTextureAccess.reset(texture, params);
             fYCoord = SK_ScalarHalf;
         }