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

bench/MemoryBench.cpp

Index: bench/MemoryBench.cpp
diff --git a/bench/MemoryBench.cpp b/bench/MemoryBench.cpp
index 05ec83b3e0a1437bfa9795d3c9c408c5383d2f58..c2c9a1ae338280f8b76f9875a649d86101c42f23 100644
--- a/bench/MemoryBench.cpp
+++ b/bench/MemoryBench.cpp
@@ -21,16 +21,16 @@ public:
         fName.printf("chunkalloc_" SK_SIZE_T_SPECIFIER, minSize);
     }
 
-    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 fName.c_str();
     }
 
-    virtual void onDraw(const int loops, SkCanvas*) SK_OVERRIDE {
+    void onDraw(const int loops, SkCanvas*) SK_OVERRIDE {
         size_t inc = fMinSize >> 4;
         SkASSERT(inc > 0);
         size_t total = fMinSize * 64;