create GrTestUtils.h, move some common functions into it

src/gpu/effects/GrSimpleTextureEffect.cpp

Index: src/gpu/effects/GrSimpleTextureEffect.cpp
diff --git a/src/gpu/effects/GrSimpleTextureEffect.cpp b/src/gpu/effects/GrSimpleTextureEffect.cpp
index 76eece4af155669902a25ec1df6190da598f9ab7..13fd1cf24e6ad0c9dea9187f497e3d0251934cfe 100644
--- a/src/gpu/effects/GrSimpleTextureEffect.cpp
+++ b/src/gpu/effects/GrSimpleTextureEffect.cpp
@@ -80,6 +80,6 @@ GrFragmentProcessor* GrSimpleTextureEffect::TestCreate(SkRandom* random,
     };
     GrCoordSet coordSet = kCoordSets[random->nextULessThan(SK_ARRAY_COUNT(kCoordSets))];
 
-    const SkMatrix& matrix = GrProcessorUnitTest::TestMatrix(random);
+    const SkMatrix& matrix = GrTest::TestMatrix(random);
     return GrSimpleTextureEffect::Create(textures[texIdx], matrix, coordSet);
 }