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

samplecode/SampleTiling.cpp

Index: samplecode/SampleTiling.cpp
diff --git a/samplecode/SampleTiling.cpp b/samplecode/SampleTiling.cpp
index cc3b52915d50eab3051f0fe62c04fae3a2593262..a59a8021b6c4c62b2b94f97945e1ea7bc11bc7a5 100644
--- a/samplecode/SampleTiling.cpp
+++ b/samplecode/SampleTiling.cpp
@@ -21,7 +21,6 @@
 
 // effects
 #include "SkGradientShader.h"
-#include "SkUnitMappers.h"
 #include "SkBlurMask.h"
 #include "SkBlurDrawLooper.h"
 
@@ -35,16 +34,9 @@ static void makebm(SkBitmap* bm, SkColorType ct, int w, int h) {
     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, um))->unref();
+                SK_ARRAY_COUNT(colors), SkShader::kClamp_TileMode))->unref();
     canvas.drawPaint(paint);
 }