Improve --trace-service to help track down problems in full_coverage_test.

runtime/observatory/tests/service/test_helper.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test_helper;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:observatory/service_io.dart';
@@ skipping 23 matching lines @@
     assert(pause_on_start != null);
     assert(pause_on_exit != null);
     assert(trace_service != null);
     // TODO(turnidge): I have temporarily turned on service tracing for
     // all tests to help diagnose flaky tests.
     trace_service = true;
     String dartExecutable = Platform.executable;
     var fullArgs = [];
     if (trace_service) {
       fullArgs.add('--trace-service');
+      fullArgs.add('--trace-service-verbose');
     }
     if (trace_compiler) {
       fullArgs.add('--trace-compiler');
     }
     if (pause_on_start) {
       fullArgs.add('--pause-isolates-on-start');
     }
     if (pause_on_exit) {
       fullArgs.add('--pause-isolates-on-exit');
     }
@@ skipping 396 matching lines @@
       }, onError: (e, st) {
         process.requestExit();
         if (!_isWebSocketDisconnect(e)) {
           print('Unexpected exception in service tests: $e $st');
           throw e;
         }
       });
     });
   }
 }