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/AAClipBench.cpp b/bench/AAClipBench.cpp
index f85af68..276a8ff 100644
--- a/bench/AAClipBench.cpp
+++ b/bench/AAClipBench.cpp
@@ -208,7 +208,7 @@
 
 protected:
     virtual const char* onGetName() { return fName.c_str(); }
-    virtual void onDraw(SkCanvas* canvas) {
+    virtual void onDraw(SkCanvas*) {
         SkPaint paint;
         this->setupPaint(&paint);
 
@@ -243,7 +243,7 @@
 
 protected:
     virtual const char* onGetName() { return "aaclip_setregion"; }
-    virtual void onDraw(SkCanvas* canvas) {
+    virtual void onDraw(SkCanvas*) {
         for (int i = 0; i < N; ++i) {
             SkAAClip clip;
             clip.setRegion(fRegion);