Address warnings from clang build bot

http://codereview.appspot.com/6506111/



git-svn-id: http://skia.googlecode.com/svn/trunk@5518 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleLayers.cpp b/samplecode/SampleLayers.cpp
index 95061b5..6d57c2a 100644
--- a/samplecode/SampleLayers.cpp
+++ b/samplecode/SampleLayers.cpp
@@ -125,15 +125,11 @@
 
 class RedFilter : public SkDrawFilter {
 public:
-    virtual bool filter(SkCanvas*, SkPaint* p, SkDrawFilter::Type) {
+    virtual void filter(SkPaint* p, SkDrawFilter::Type) SK_OVERRIDE {
         fColor = p->getColor();
         if (fColor == SK_ColorRED) {
             p->setColor(SK_ColorGREEN);
         }
-        return true;
-    }
-    virtual void restore(SkCanvas*, SkPaint* p, SkDrawFilter::Type) {
-        p->setColor(fColor);
     }
 
 private: