Remove race(s) in vmservice tests.

runtime/bin/main.cc

Index: runtime/bin/main.cc
diff --git a/runtime/bin/main.cc b/runtime/bin/main.cc
index e46d7eb7d3fc872b257c96fe82e9da6f842d61ca..57c51686767da10cbc9e1982eea74ffac58bf5ba 100644
--- a/runtime/bin/main.cc
+++ b/runtime/bin/main.cc
@@ -478,7 +478,9 @@ static Dart_Isolate CreateIsolateAndSetupHelper(const char* script_uri,
       Dart_SetField(platform_type, script_name_name, dart_script);
   CHECK_RESULT(set_script_name);
 
-  VmService::SendIsolateStartupMessage(Dart_GetMainPortId());
+  Dart_Handle debug_name = Dart_DebugName();
+  CHECK_RESULT(debug_name);
+  VmService::SendIsolateStartupMessage(Dart_GetMainPortId(), debug_name);
 
   // Make the isolate runnable so that it is ready to handle messages.
   Dart_ExitScope();