Fix up -Winconsistent-missing-override

bench/TextBlobBench.cpp

Index: bench/TextBlobBench.cpp
diff --git a/bench/TextBlobBench.cpp b/bench/TextBlobBench.cpp
index ae71a1e41ab8d63a9d9e04995d2bac389a19880d..f830001ea9b3bc13c98ecf0497147e4adbf3862a 100644
--- a/bench/TextBlobBench.cpp
+++ b/bench/TextBlobBench.cpp
@@ -50,11 +50,11 @@ protected:
         fBlob.reset(builder.build());
     }
 
-    const char* onGetName() {
+    const char* onGetName() override {
         return "TextBlobBench";
     }
 
-    void onDraw(const int loops, SkCanvas* canvas) {
+    void onDraw(const int loops, SkCanvas* canvas) override {
         SkPaint paint;
 
         // To ensure maximum caching, we just redraw the blob at the same place everytime