Revert of Remove unused (by clients) SkUnitMapper (https://codereview.chromium.org/283273002/)

gm/tilemodes.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "gm.h"
 #include "SkPath.h"
 #include "SkRegion.h"
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "SkColorPriv.h"
 #include "SkColorFilter.h"
 #include "SkTypeface.h"
 
 // effects
 #include "SkGradientShader.h"
+#include "SkUnitMappers.h"
 #include "SkBlurDrawLooper.h"
 
 static void makebm(SkBitmap* bm, SkColorType ct, int w, int h) {
     bm->allocPixels(SkImageInfo::Make(w, h, ct, kPremul_SkAlphaType));
     bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas    canvas(*bm);
     SkPoint     pts[] = { { 0, 0 }, { SkIntToScalar(w), SkIntToScalar(h)} };
     SkColor     colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
     SkScalar    pos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
     SkPaint     paint;
 
+    SkUnitMapper*   um = NULL;
+
+    um = new SkCosineMapper;
+//    um = new SkDiscreteMapper(12);
+
+    SkAutoUnref au(um);
+
     paint.setDither(true);
     paint.setShader(SkGradientShader::CreateLinear(pts, colors, pos,
-                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode))->unref();
+                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode, um))->unref();
     canvas.drawPaint(paint);
 }
 
 static void setup(SkPaint* paint, const SkBitmap& bm, bool filter,
                   SkShader::TileMode tmx, SkShader::TileMode tmy) {
     SkShader* shader = SkShader::CreateBitmapShader(bm, tmx, tmy);
     paint->setShader(shader)->unref();
     paint->setFilterLevel(filter ? SkPaint::kLow_FilterLevel : SkPaint::kNone_FilterLevel);
 }
 
@@ skipping 213 matching lines @@
 private:
     typedef skiagm::GM INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new TilingGM(true); )
 DEF_GM( return new TilingGM(false); )
 DEF_GM( return new Tiling2GM(make_bm, "bitmap"); )
 DEF_GM( return new Tiling2GM(make_grad, "gradient"); )