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

gm/shadertext3.cpp

Index: gm/shadertext3.cpp
diff --git a/gm/shadertext3.cpp b/gm/shadertext3.cpp
index 3c6400d8d65cb8b6a99869e6b01d43417fc96cdc..8aa6e6965c432685eb2bbdb8387b17d831d00ab5 100644
--- a/gm/shadertext3.cpp
+++ b/gm/shadertext3.cpp
@@ -4,10 +4,10 @@
  * 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 {
 
@@ -26,8 +26,14 @@
 
     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();