remove unused (by clients) SkUnitMapper

BUG=skia:
R=robertphillips@google.com, scroggo@google.com, george@mozilla.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/283273002

git-svn-id: http://skia.googlecode.com/svn/trunk@14761 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SamplePatch.cpp b/samplecode/SamplePatch.cpp
index 09eb42f..fe94bbf 100644
--- a/samplecode/SamplePatch.cpp
+++ b/samplecode/SamplePatch.cpp
@@ -42,7 +42,7 @@
                       { SkIntToScalar(size.fX), SkIntToScalar(size.fY) } };
     SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
     return SkGradientShader::CreateLinear(pts, colors, NULL,
-                    SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode, NULL);
+                    SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode);
 }
 
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