diff --git a/test/cpp/microbenchmarks/bm_closure.cc b/test/cpp/microbenchmarks/bm_closure.cc
index d52fe4ee309..fd540e994b0 100644
--- a/test/cpp/microbenchmarks/bm_closure.cc
+++ b/test/cpp/microbenchmarks/bm_closure.cc
@@ -84,12 +84,12 @@ BENCHMARK(BM_ClosureInitAgainstExecCtx);
 
 static void BM_ClosureInitAgainstCombiner(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
+  grpc_combiner* combiner = grpc_combiner_create();
   grpc_closure c;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     benchmark::DoNotOptimize(grpc_closure_init(
-        &c, DoNothing, NULL, grpc_combiner_scheduler(combiner, false)));
+        &c, DoNothing, NULL, grpc_combiner_scheduler(combiner)));
   }
   GRPC_COMBINER_UNREF(&exec_ctx, combiner, "finished");
   grpc_exec_ctx_finish(&exec_ctx);
@@ -259,10 +259,9 @@ BENCHMARK(BM_TryAcquireSpinlock);
 
 static void BM_ClosureSchedOnCombiner(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
+  grpc_combiner* combiner = grpc_combiner_create();
   grpc_closure c;
-  grpc_closure_init(&c, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
+  grpc_closure_init(&c, DoNothing, NULL, grpc_combiner_scheduler(combiner));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_closure_sched(&exec_ctx, &c, GRPC_ERROR_NONE);
@@ -276,13 +275,11 @@ BENCHMARK(BM_ClosureSchedOnCombiner);
 
 static void BM_ClosureSched2OnCombiner(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
+  grpc_combiner* combiner = grpc_combiner_create();
   grpc_closure c1;
   grpc_closure c2;
-  grpc_closure_init(&c1, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
-  grpc_closure_init(&c2, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
+  grpc_closure_init(&c1, DoNothing, NULL, grpc_combiner_scheduler(combiner));
+  grpc_closure_init(&c2, DoNothing, NULL, grpc_combiner_scheduler(combiner));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_closure_sched(&exec_ctx, &c1, GRPC_ERROR_NONE);
@@ -297,16 +294,13 @@ BENCHMARK(BM_ClosureSched2OnCombiner);
 
 static void BM_ClosureSched3OnCombiner(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
+  grpc_combiner* combiner = grpc_combiner_create();
   grpc_closure c1;
   grpc_closure c2;
   grpc_closure c3;
-  grpc_closure_init(&c1, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
-  grpc_closure_init(&c2, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
-  grpc_closure_init(&c3, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner, false));
+  grpc_closure_init(&c1, DoNothing, NULL, grpc_combiner_scheduler(combiner));
+  grpc_closure_init(&c2, DoNothing, NULL, grpc_combiner_scheduler(combiner));
+  grpc_closure_init(&c3, DoNothing, NULL, grpc_combiner_scheduler(combiner));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_closure_sched(&exec_ctx, &c1, GRPC_ERROR_NONE);
@@ -322,14 +316,12 @@ BENCHMARK(BM_ClosureSched3OnCombiner);
 
 static void BM_ClosureSched2OnTwoCombiners(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner1 = grpc_combiner_create(NULL);
-  grpc_combiner* combiner2 = grpc_combiner_create(NULL);
+  grpc_combiner* combiner1 = grpc_combiner_create();
+  grpc_combiner* combiner2 = grpc_combiner_create();
   grpc_closure c1;
   grpc_closure c2;
-  grpc_closure_init(&c1, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner1, false));
-  grpc_closure_init(&c2, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner2, false));
+  grpc_closure_init(&c1, DoNothing, NULL, grpc_combiner_scheduler(combiner1));
+  grpc_closure_init(&c2, DoNothing, NULL, grpc_combiner_scheduler(combiner2));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_closure_sched(&exec_ctx, &c1, GRPC_ERROR_NONE);
@@ -345,20 +337,16 @@ BENCHMARK(BM_ClosureSched2OnTwoCombiners);
 
 static void BM_ClosureSched4OnTwoCombiners(benchmark::State& state) {
   TrackCounters track_counters;
-  grpc_combiner* combiner1 = grpc_combiner_create(NULL);
-  grpc_combiner* combiner2 = grpc_combiner_create(NULL);
+  grpc_combiner* combiner1 = grpc_combiner_create();
+  grpc_combiner* combiner2 = grpc_combiner_create();
   grpc_closure c1;
   grpc_closure c2;
   grpc_closure c3;
   grpc_closure c4;
-  grpc_closure_init(&c1, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner1, false));
-  grpc_closure_init(&c2, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner2, false));
-  grpc_closure_init(&c3, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner1, false));
-  grpc_closure_init(&c4, DoNothing, NULL,
-                    grpc_combiner_scheduler(combiner2, false));
+  grpc_closure_init(&c1, DoNothing, NULL, grpc_combiner_scheduler(combiner1));
+  grpc_closure_init(&c2, DoNothing, NULL, grpc_combiner_scheduler(combiner2));
+  grpc_closure_init(&c3, DoNothing, NULL, grpc_combiner_scheduler(combiner1));
+  grpc_closure_init(&c4, DoNothing, NULL, grpc_combiner_scheduler(combiner2));
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   while (state.KeepRunning()) {
     grpc_closure_sched(&exec_ctx, &c1, GRPC_ERROR_NONE);
@@ -418,8 +406,8 @@ BENCHMARK(BM_ClosureReschedOnExecCtx);
 static void BM_ClosureReschedOnCombiner(benchmark::State& state) {
   TrackCounters track_counters;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
-  Rescheduler r(state, grpc_combiner_scheduler(combiner, false));
+  grpc_combiner* combiner = grpc_combiner_create();
+  Rescheduler r(state, grpc_combiner_scheduler(combiner));
   r.ScheduleFirst(&exec_ctx);
   grpc_exec_ctx_flush(&exec_ctx);
   GRPC_COMBINER_UNREF(&exec_ctx, combiner, "finished");
@@ -431,10 +419,10 @@ BENCHMARK(BM_ClosureReschedOnCombiner);
 static void BM_ClosureReschedOnCombinerFinally(benchmark::State& state) {
   TrackCounters track_counters;
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_combiner* combiner = grpc_combiner_create(NULL);
-  Rescheduler r(state, grpc_combiner_finally_scheduler(combiner, false));
-  r.ScheduleFirstAgainstDifferentScheduler(
-      &exec_ctx, grpc_combiner_scheduler(combiner, false));
+  grpc_combiner* combiner = grpc_combiner_create();
+  Rescheduler r(state, grpc_combiner_finally_scheduler(combiner));
+  r.ScheduleFirstAgainstDifferentScheduler(&exec_ctx,
+                                           grpc_combiner_scheduler(combiner));
   grpc_exec_ctx_flush(&exec_ctx);
   GRPC_COMBINER_UNREF(&exec_ctx, combiner, "finished");
   grpc_exec_ctx_finish(&exec_ctx);