Add debugging output to crash_dump_test to help track down timeout.

runtime/observatory/tests/service/crash_dump_test.dart

 // Copyright (c) 2015, 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 crash_dump_test;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:observatory/service_io.dart';
 
 import 'test_helper.dart';
 
 Future warmup() async {
   print('hi');
 }
 
 var tests = [
   (VM vm) async {
     HttpClient client = new HttpClient();
+    print('Requesting uri ${serviceHttpAddress}/_getCrashDump');
     var request =
         await client.getUrl(Uri.parse('$serviceHttpAddress/_getCrashDump'));
     var response = await request.close();
+    print('Received response');
     Completer completer = new Completer();
     StringBuffer sb = new StringBuffer();
     response.transform(UTF8.decoder).listen((chunk) {
       sb.write(chunk);
     }, onDone: () => completer.complete(sb.toString()));
     var responseString = await completer.future;
     JSON.decode(responseString);
   }
 ];
 
 main(args) async => runVMTests(args, tests, testeeBefore:warmup);