Bench : Unused parameters cleanup

I removed unused parameters in bench wherever it was trivial to do so.
Review URL: https://codereview.appspot.com/7411046

git-svn-id: http://skia.googlecode.com/svn/trunk@7988 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/PathBench.cpp b/bench/PathBench.cpp
index b0794f6..658ee96 100644
--- a/bench/PathBench.cpp
+++ b/bench/PathBench.cpp
@@ -819,7 +819,7 @@
         return fName.c_str();
     }
 
-    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+    virtual void onDraw(SkCanvas*) SK_OVERRIDE {
         for (int i = 0; i < N; ++i) {
             const SkRect& rect = fQueryRects[i % kQueryRectCnt];
             fParity = fParity != fPath.conservativelyContainsRect(rect);