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

gm/shadertext3.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 "SkCanvas.h"
 #include "SkGradientShader.h"
+#include "SkUnitMappers.h"
 
 namespace skiagm {
 
 static void makebm(SkBitmap* bm, int w, int h) {
     bm->allocN32Pixels(w, h);
     bm->eraseColor(SK_ColorTRANSPARENT);
 
     SkCanvas    canvas(*bm);
     SkScalar    s = SkIntToScalar(SkMin32(w, h));
     static const SkPoint     kPts0[] = { { 0, 0 }, { s, s } };
     static const SkPoint     kPts1[] = { { s/2, 0 }, { s/2, s } };
     static const SkScalar    kPos[] = { 0, SK_Scalar1/2, SK_Scalar1 };
     static const SkColor kColors0[] = {0x80F00080, 0xF0F08000, 0x800080F0 };
     static const SkColor kColors1[] = {0xF08000F0, 0x8080F000, 0xF000F080 };
 
 
     SkPaint     paint;
 
+    SkUnitMapper*   um = NULL;
+
+    um = new SkCosineMapper;
+
+    SkAutoUnref au(um);
+
     paint.setShader(SkGradientShader::CreateLinear(kPts0, kColors0, kPos,
-                    SK_ARRAY_COUNT(kColors0), SkShader::kClamp_TileMode))->unref();
+                    SK_ARRAY_COUNT(kColors0), SkShader::kClamp_TileMode, um))->unref();
     canvas.drawPaint(paint);
     paint.setShader(SkGradientShader::CreateLinear(kPts1, kColors1, kPos,
                     SK_ARRAY_COUNT(kColors1), SkShader::kClamp_TileMode))->unref();
     canvas.drawPaint(paint);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 struct LabeledMatrix {
     SkMatrix    fMatrix;
@@ skipping 90 matching lines @@
 private:
     SkBitmap fBmp;
     typedef GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static GM* MyFactory(void*) { return new ShaderText3GM; }
 static GMRegistry reg(MyFactory);
 }