Address some valgrind issues

https://codereview.appspot.com/7448051/



git-svn-id: http://skia.googlecode.com/svn/trunk@7966 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/GradientTest.cpp b/tests/GradientTest.cpp
index e60c9ed..41724b6 100644
--- a/tests/GradientTest.cpp
+++ b/tests/GradientTest.cpp
@@ -52,6 +52,7 @@
     REPORTER_ASSERT(reporter, SkShader::kColor_GradientType == s->asAGradient(NULL));
 
     SkShader::GradientInfo info;
+    info.fColors = NULL;
     info.fColorCount = 0;
     s->asAGradient(&info);
     REPORTER_ASSERT(reporter, 1 == info.fColorCount);