Split up into a new service proto, use proper service suffix, add a
reset option to the mark, create a closed loop config params (empty
message) for consistency with other tests.
diff --git a/test/cpp/qps/timer.cc b/test/cpp/qps/timer.cc
index 8edb838..3ec7f49 100644
--- a/test/cpp/qps/timer.cc
+++ b/test/cpp/qps/timer.cc
@@ -61,7 +61,7 @@
   return r;
 }
 
-Timer::Result Timer::Mark() {
+Timer::Result Timer::Mark() const {
   Result s = Sample();
   Result r;
   r.wall = s.wall - start_.wall;