Fix android.

Oops.

TBR=vardhan@google.com

Review URL: https://codereview.chromium.org/1987033002 .
diff --git a/services/notifications/apptests/notifications_apptest.cc b/services/notifications/apptests/notifications_apptest.cc
index d61fd63..b057c36 100644
--- a/services/notifications/apptests/notifications_apptest.cc
+++ b/services/notifications/apptests/notifications_apptest.cc
@@ -6,6 +6,7 @@
 #include "base/message_loop/message_loop.h"
 #include "mojo/public/cpp/application/application_test_base.h"
 #include "mojo/public/cpp/application/connect.h"
+#include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/callback.h"
 #include "mojo/public/cpp/environment/logging.h"
 #include "mojo/public/cpp/system/macros.h"