Mark reload_sources_test as slow

runtime/observatory/tests/service/service.status

Index: runtime/observatory/tests/service/service.status
diff --git a/runtime/observatory/tests/service/service.status b/runtime/observatory/tests/service/service.status
index fe22d15516f2deaaecf3774d6e96c297acfef0b2..68101378d8b3a390d1ab8d0011362cd29001dfa4 100644
--- a/runtime/observatory/tests/service/service.status
+++ b/runtime/observatory/tests/service/service.status
@@ -7,6 +7,8 @@ vm_timeline_flags_test: Pass, RuntimeError # Issue 26483
 gc_test: Pass, RuntimeError # Issue 26490
 pause_on_start_and_exit_test: Pass, RuntimeError # Issue 26470
 pause_on_start_then_step_test: Pass, RuntimeError # Issue 26470
+# Reload is slow on the bots
+reload_sources_test: Pass, Slow
 
 [ ($compiler == none || $compiler == precompiler) && ($runtime == vm || $runtime == dart_precompiled) ]
 evaluate_activation_test/instance: RuntimeError # http://dartbug.com/20047
@@ -18,6 +20,7 @@ isolate_lifecycle_test: Pass, RuntimeError # Issue 24174
 debugger_location_second_test: Pass, Slow
 debugger_location_test: Pass, Slow
 
+
 # Disable on simulators.
 [ $arch == simarm || $arch == simmips || $arch == simarm64 ]
 *: SkipSlow