Add missing pieces of my last CL

runtime/observatory/tests/service/set_library_debuggable_test.dart

Index: runtime/observatory/tests/service/set_library_debuggable_test.dart
diff --git a/runtime/observatory/tests/service/set_library_debuggable_test.dart b/runtime/observatory/tests/service/set_library_debuggable_test.dart
index d76569c5d1849d64271a25e672ab40e3af1e9ed1..6873e446438fa77e566030bf5484cf4f949dede7 100644
--- a/runtime/observatory/tests/service/set_library_debuggable_test.dart
+++ b/runtime/observatory/tests/service/set_library_debuggable_test.dart
@@ -23,11 +23,13 @@ testMain() async {
 }
 
 var tests = [
+  hasStoppedAtBreakpoint,
+  markDartColonLibrariesDebuggable,
   (Isolate isolate) async {
     await isolate.reload();
     Library dartCore = isolate.libraries.firstWhere(
       (Library library) => library.uri == 'dart:core');
-    await dartCore.load();
+    await dartCore.reload();
     expect(dartCore.debuggable, equals(true));
   },
   stoppedInFunction('testMain', contains:true),