make the filter mode for GrTextureAccess an enum so we can plumb down

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 6dcbb05f7e1eae0b19dcdb9bfa7dad6d021fc22f..de43b69a2f70b78c1b4e3f667f9c357f2cf52b28 100644
--- a/src/effects/gradients/SkGradientShader.cpp
+++ b/src/effects/gradients/SkGradientShader.cpp
@@ -914,7 +914,7 @@ GrGradientEffect::GrGradientEffect(GrContext* ctx,
 
     // We always filter the gradient table. Each table is one row of a texture, so always y-clamp.
     GrTextureParams params;
-    params.setBilerp(true);
+    params.setFilterMode(GrTextureParams::kBilerp_FilterMode);
     params.setTileModeX(tileMode);
 
     fRow = fAtlas->lockRow(bitmap);