Fix up all the easy virtual ... SK_OVERRIDE cases.

bench/WriterBench.cpp

Index: bench/WriterBench.cpp
diff --git a/bench/WriterBench.cpp b/bench/WriterBench.cpp
index 906a9d2ee841e0624138e2a6f599a87ca219eea6..4dcd3a3d0796a393cb0f818db731769fe63ab150 100644
--- a/bench/WriterBench.cpp
+++ b/bench/WriterBench.cpp
@@ -12,16 +12,16 @@
 
 class WriterBench : public Benchmark {
 public:
-    virtual bool isSuitableFor(Backend backend) SK_OVERRIDE {
+    bool isSuitableFor(Backend backend) SK_OVERRIDE {
         return backend == kNonRendering_Backend;
     }
 
 protected:
-    virtual const char* onGetName() SK_OVERRIDE {
+    const char* onGetName() SK_OVERRIDE {
         return "writer";
     }
 
-    virtual void onDraw(const int loops, SkCanvas*) SK_OVERRIDE {
+    void onDraw(const int loops, SkCanvas*) SK_OVERRIDE {
         static const char gStr[] = "abcdefghimjklmnopqrstuvwxyz";
         static const size_t gLen = strlen(gStr);
         SkWriter32 writer;