Only start http server for browser tests.

tools/test-runtime.dart

 #!/usr/bin/env dart
 // Copyright (c) 2012, 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.
 
 // TODO(ager): Get rid of this version of test.dart when we don't have
 // to worry about the special runtime checkout anymore.
 // This file is identical to test.dart with test suites in the
 // directories samples, client, compiler, and utils removed.
 
@@ skipping 74 matching lines @@
       if (selectors.containsKey(name)) {
         queue.addTestSuite(
             new StandardTestSuite.forDirectory(conf, testSuiteDir));
       }
     }
   }
 
   // Start global http server that serves the entire dart repo.
   // The http server is available on localhost:9876 for any
   // test that needs to load resources from the repo over http.
-  startHttpServer('127.0.0.1', 9876);
+  if (!listTests) {
+    // Only start the server if we are running browser tests.
+    var runningBrowserTests = configurations.some((config) {
+      return TestUtils.isBrowserRuntime(config['runtime']);
+    });
+    if (runningBrowserTests) startHttpServer('127.0.0.1', 9876);
+  }
 
   // Start process queue.
   new ProcessQueue(
       maxProcesses,
       progressIndicator,
       startTime,
       printTiming,
       enqueueConfiguration,
       () => terminateHttpServer(),
       verbose,
       listTests);
 }