Merge pull request #2205 from nicolasnoble/threadpools-need-to-cascade-kick

Cascade-kick pollsets when shutting down.

src/core/surface/completion_queue.c

@@ -208,6 +208,7 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
     }
     if (cc->shutdown) {
       ev = create_shutdown_event();
+      grpc_pollset_kick(&cc->pollset);
       break;
     }
     if (!grpc_pollset_work(&cc->pollset, deadline)) {