Remove unused (by clients) SkUnitMapper

This reverts commit 874423a81b5bc2541c7397e6ab00d5e7c9fdaf98.

TBR=scroggo

Author: reed@google.com

Review URL: https://codereview.chromium.org/288313009

git-svn-id: http://skia.googlecode.com/svn/trunk@14842 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gradient_matrix.cpp b/gm/gradient_matrix.cpp
index 4f2915a..275acc8 100644
--- a/gm/gradient_matrix.cpp
+++ b/gm/gradient_matrix.cpp
@@ -63,7 +63,7 @@
 
 static SkShader* make_linear_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) {
     return SkGradientShader::CreateLinear(pts, gColors, NULL, SK_ARRAY_COUNT(gColors),
-                                          SkShader::kClamp_TileMode, NULL, 0, &localMatrix);
+                                          SkShader::kClamp_TileMode, 0, &localMatrix);
 }
 
 static SkShader* make_radial_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) {
@@ -72,7 +72,7 @@
                SkScalarAve(pts[0].fY, pts[1].fY));
     float radius = (center - pts[0]).length();
     return SkGradientShader::CreateRadial(center, radius, gColors, NULL, SK_ARRAY_COUNT(gColors),
-                                          SkShader::kClamp_TileMode, NULL, 0, &localMatrix);
+                                          SkShader::kClamp_TileMode, 0, &localMatrix);
 }
 
 static void draw_gradients(SkCanvas* canvas,