Merge pull request #10383 from ctiller/base16

Add new benchmark

tools/profiling/microbenchmarks/bm_json.py

@@ -117,6 +117,10 @@ _BM_SPECS = {
   'BM_StreamingPingPongWithCoalescingApi': {
     'tpl': ['fixture', 'client_mutator', 'server_mutator'],
     'dyn': ['request_size', 'request_count', 'end_of_stream'],
+  },
+  'BM_Base16SomeStuff': {
+    'tpl': [],
+    'dyn': ['request_size'],
   }
 }