Removed unused parameters

I removed unused parameters wherever it was trivial to do so.
Review URL: https://codereview.chromium.org/12772003

git-svn-id: http://skia.googlecode.com/svn/trunk@8103 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleCircle.cpp b/samplecode/SampleCircle.cpp
index aca7460..f65ba01 100644
--- a/samplecode/SampleCircle.cpp
+++ b/samplecode/SampleCircle.cpp
@@ -15,7 +15,7 @@
 // fractional, and the impl computes the center and radii, and uses them to
 // reconstruct the edges of the circle.
 // see bug# 1504910
-static void test_circlebounds(SkCanvas* canvas) {
+static void test_circlebounds(SkCanvas*) {
 #ifdef SK_SCALAR_IS_FLOAT
     SkRect r = { 1.39999998f, 1, 21.3999996f, 21 };
     SkPath p;