By default, don't use observatory during integration tests.

pkg/analysis_server/test/integration/integration_tests.dart

 // Copyright (c) 2014, 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.integration.analysis;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io';
@@ skipping 667 matching lines @@
     return dirname(pathname);
   }
 
   /**
    * Start the server.  If [debugServer] is `true`, the server will be started
    * with "--debug", allowing a debugger to be attached. If [profileServer] is
    * `true`, the server will be started with "--observe" and
    * "--pause-isolates-on-exit", allowing the observatory to be used.
    */
   Future start(NotificationProcessor notificationProcessor, {bool debugServer:
-      false, bool profileServer: true}) {
+      false, bool profileServer: false}) {
     if (_process != null) {
       throw new Exception('Process already started');
     }
     _time.start();
     String dartBinary = Platform.executable;
     String rootDir =
         findRoot(Platform.script.toFilePath(windows: Platform.isWindows));
     String serverPath = normalize(join(rootDir, 'bin', 'server.dart'));
     List<String> arguments = [];
     if (debugServer) {
@@ skipping 166 matching lines @@
    */
   void _recordStdio(String line) {
     double elapsedTime = _time.elapsedTicks / _time.frequency;
     line = "$elapsedTime: $line";
     if (_debuggingStdio) {
       print(line);
     }
     _recordedStdio.add(line);
   }
 }