Add rich closure debug mode
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
index 0e2b413..307e3ba 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.c
@@ -118,7 +118,7 @@
   while (pp != NULL) {
     pending_pick *next = pp->next;
     *pp->target = NULL;
-    grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+    GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
     gpr_free(pp);
     pp = next;
   }
@@ -135,7 +135,7 @@
     pending_pick *next = pp->next;
     if (pp->target == target) {
       *target = NULL;
-      grpc_closure_sched(exec_ctx, pp->on_complete,
+      GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete,
                          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
                              "Pick Cancelled", &error, 1));
       gpr_free(pp);
@@ -160,7 +160,7 @@
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_closure_sched(exec_ctx, pp->on_complete,
+      GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete,
                          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
                              "Pick Cancelled", &error, 1));
       gpr_free(pp);
@@ -258,7 +258,7 @@
   if (p->selected) {
     grpc_connected_subchannel_ping(exec_ctx, p->selected, closure);
   } else {
-    grpc_closure_sched(exec_ctx, closure,
+    GRPC_CLOSURE_SCHED(exec_ctx, closure,
                        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected"));
   }
 }
@@ -557,7 +557,7 @@
                     "Servicing pending pick with selected subchannel %p",
                     (void *)p->selected);
           }
-          grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+          GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
           gpr_free(pp);
         }
         grpc_connected_subchannel_notify_on_state_change(
@@ -610,7 +610,7 @@
           while ((pp = p->pending_picks)) {
             p->pending_picks = pp->next;
             *pp->target = NULL;
-            grpc_closure_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
+            GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete, GRPC_ERROR_NONE);
             gpr_free(pp);
           }
           GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base,
@@ -654,7 +654,7 @@
   pick_first_lb_policy *p = gpr_zalloc(sizeof(*p));
   pf_update_locked(exec_ctx, &p->base, args);
   grpc_lb_policy_init(&p->base, &pick_first_lb_policy_vtable, args->combiner);
-  grpc_closure_init(&p->connectivity_changed, pf_connectivity_changed_locked, p,
+  GRPC_CLOSURE_INIT(&p->connectivity_changed, pf_connectivity_changed_locked, p,
                     grpc_combiner_scheduler(args->combiner));
   return &p->base;
 }