Removed unused parameters

I removed unused parameters wherever it was trivial to do so.
Review URL: https://codereview.chromium.org/12469002

git-svn-id: http://skia.googlecode.com/svn/trunk@8068 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/effects/GrConvolutionEffect.cpp b/src/gpu/effects/GrConvolutionEffect.cpp
index 1c0e8f5..794a936 100644
--- a/src/gpu/effects/GrConvolutionEffect.cpp
+++ b/src/gpu/effects/GrConvolutionEffect.cpp
@@ -180,7 +180,7 @@
 GR_DEFINE_EFFECT_TEST(GrConvolutionEffect);
 
 GrEffectRef* GrConvolutionEffect::TestCreate(SkMWCRandom* random,
-                                             GrContext* context,
+                                             GrContext*,
                                              GrTexture* textures[]) {
     int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
                                       GrEffectUnitTest::kAlphaTextureIdx;