Reduce test.dart memory usage.

tools/testing/dart/http_server.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 http_server;
 
 import 'dart:async';
 import 'dart:io';
 import 'test_suite.dart';  // For TestUtils.
 // TODO(efortuna): Rewrite to not use the args library and simply take an
@@ skipping 98 matching lines @@
   List _serverList = [];
   Path _buildDirectory = null;
   Path _dartDirectory = null;
   final bool useContentSecurityPolicy;
   final String runtime;
 
   TestingServers(Path buildDirectory,
                  this.useContentSecurityPolicy,
                  [String this.runtime = 'none', String dartDirectory]) {
     _buildDirectory = TestUtils.absolutePath(buildDirectory);
-    _dartDirectory = dartDirectory == null ? TestUtils.dartDir()
+    _dartDirectory = dartDirectory == null ? TestUtils.dartDir
         : new Path(dartDirectory);
   }
 
   int get port => _serverList[0].port;
   int get crossOriginPort => _serverList[1].port;
 
   /**
    * [startServers] will start two Http servers.
    * The first server listens on [port] and sets
    *   "Access-Control-Allow-Origin: *"
    * The second server listens on [crossOriginPort] and sets
    *   "Access-Control-Allow-Origin: client:port1
    *   "Access-Control-Allow-Credentials: true"
    */
   Future startServers(String host, {int port: 0, int crossOriginPort: 0}) {
     return _startHttpServer(host, port: port).then((server) {
       return _startHttpServer(host,
                               port: crossOriginPort,
                               allowedPort:_serverList[0].port);
     });
   }
 
   String httpServerCommandline() {
     var dart = TestUtils.dartTestExecutable.toNativePath();
-    var dartDir = TestUtils.dartDir();
+    var dartDir = TestUtils.dartDir;
     var script = dartDir.join(new Path("tools/testing/dart/http_server.dart"));
     var buildDirectory = _buildDirectory.toNativePath();
     var csp = useContentSecurityPolicy ? '--csp ' : '';
     return '$dart $script -p $port -c $crossOriginPort $csp'
            '--build-directory=$buildDirectory --runtime=$runtime';
   }
 
   void stopServers() {
     for (var server in _serverList) {
       server.close();
@@ skipping 242 matching lines @@
 class _Entry implements Comparable {
   final String name;
   final String displayName;
 
   _Entry(this.name, this.displayName);
 
   int compareTo(_Entry other) {
     return name.compareTo(other.name);
   }
 }