Enable JSON reports for qps drivers
diff --git a/test/cpp/util/benchmark_config.cc b/test/cpp/util/benchmark_config.cc
index ca4c27e..6fc8640 100644
--- a/test/cpp/util/benchmark_config.cc
+++ b/test/cpp/util/benchmark_config.cc
@@ -37,6 +37,9 @@
 DEFINE_bool(enable_log_reporter, true,
             "Enable reporting of benchmark results through GprLog");
 
+DEFINE_string(scenario_result_file, "",
+              "Write JSON benchmark report to the file specified.");
+
 DEFINE_string(hashed_id, "", "Hash of the user id");
 
 DEFINE_string(test_name, "", "Name of the test being executed");
@@ -68,6 +71,10 @@
     composite_reporter->add(
         std::unique_ptr<Reporter>(new GprLogReporter("LogReporter")));
   }
+  if (FLAGS_scenario_result_file != "") {
+    composite_reporter->add(std::unique_ptr<Reporter>(
+        new JsonReporter("JsonReporter", FLAGS_scenario_result_file)));
+  }
 
   return std::shared_ptr<Reporter>(composite_reporter);
 }