Delete dead subset benches from nanobench

bench/subset/SubsetTranslateBench.h

Index: bench/subset/SubsetTranslateBench.h
diff --git a/bench/subset/SubsetTranslateBench.h b/bench/subset/SubsetTranslateBench.h
index 298732c8512cfb2426609ff87246e206e14024da..49682d37c78b560e347858b427c544099218ac88 100644
--- a/bench/subset/SubsetTranslateBench.h
+++ b/bench/subset/SubsetTranslateBench.h
@@ -23,8 +23,7 @@ public:
     SubsetTranslateBench(const SkString& path,
                          SkColorType colorType,
                          uint32_t subsetWidth,
-                         uint32_t subsetHeight,
-                         bool useCodec);
+                         uint32_t subsetHeight);
 
 protected:
     const char* onGetName() override;
@@ -36,7 +35,6 @@ private:
     SkColorType                   fColorType;
     const uint32_t                fSubsetWidth;
     const uint32_t                fSubsetHeight;
-    const bool                    fUseCodec;
     SkAutoTDelete<SkMemoryStream> fStream;
     typedef Benchmark INHERITED;
 };