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/SampleLayers.cpp b/samplecode/SampleLayers.cpp
index b1311ee..f72c519 100644
--- a/samplecode/SampleLayers.cpp
+++ b/samplecode/SampleLayers.cpp
@@ -260,7 +260,7 @@
         return this->INHERITED::onClick(click);
     }
 
-    virtual bool handleKey(SkKey key) {
+    virtual bool handleKey(SkKey) {
         this->inval(NULL);
         return true;
     }