Fix Gradient2Bench colors so that Debug bench will run.


git-svn-id: http://skia.googlecode.com/svn/trunk@1639 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/GradientBench.cpp b/bench/GradientBench.cpp
index d10625b..e017732 100644
--- a/bench/GradientBench.cpp
+++ b/bench/GradientBench.cpp
@@ -170,7 +170,8 @@
         const SkPoint pts[] = { 0, 0, SkIntToScalar(100), SkIntToScalar(100) };
 
         for (int i = 0; i < 1000; i++) {
-            SkColor colors[] = { SK_ColorBLACK, SkColorSetARGB(i, i, i, i), SK_ColorWHITE };
+            const int a = i % 256;
+            SkColor colors[] = { SK_ColorBLACK, SkColorSetARGB(a, a, a, a), SK_ColorWHITE };
             SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL,
                                                          SK_ARRAY_COUNT(colors),
                                                          SkShader::kClamp_TileMode);