Merge pull request #13952 from vjpai/functional

Need to include functional to use std::bind
diff --git a/test/core/transport/chttp2/settings_timeout_test.cc b/test/core/transport/chttp2/settings_timeout_test.cc
index 08473c7..d7d6ee7 100644
--- a/test/core/transport/chttp2/settings_timeout_test.cc
+++ b/test/core/transport/chttp2/settings_timeout_test.cc
@@ -21,6 +21,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include <functional>
 #include <memory>
 #include <thread>