Split debugger_location_test into two separate tests

runtime/observatory/tests/service/test_helper.dart

Index: runtime/observatory/tests/service/test_helper.dart
diff --git a/runtime/observatory/tests/service/test_helper.dart b/runtime/observatory/tests/service/test_helper.dart
index 858a23314eed7fd4fe62ffca200dd2792dfac1af..63b8fc2bb97231c11cc4683971353398e2bed074 100644
--- a/runtime/observatory/tests/service/test_helper.dart
+++ b/runtime/observatory/tests/service/test_helper.dart
@@ -226,11 +226,11 @@ class _ServiceTesteeLauncher {
           first = false;
           print('** Signaled to run test queries on $portNumber');
         }
-        print(line);
+        print('>testee>out> $line');
       });
       process.stderr.transform(UTF8.decoder)
                     .transform(new LineSplitter()).listen((line) {
-        print(line);
+        print('>testee>err> $line');
       });
       process.exitCode.then((exitCode) {
         if ((exitCode != 0) && !killedByTester) {