Change the process API to be completely asynchronous.

tests/stub-generator/test_config.dart

 // Copyright (c) 2011, 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("stub_generator_test_config");
 
 #import("../../tools/testing/dart/test_suite.dart");
 
 class StubGeneratorTestSuite extends StandardTestSuite {
   String dartcPath;
@@ skipping 94 matching lines @@
     stubsOutFile.createSync();
     String stubsPath = stubsOutFile.fullPathSync();
     List<String> args = [filename,
                          '-noincremental',
                          '-out', temp.path,
                          '-isolate-stub-out', stubsPath,
                          '-generate-isolate-stubs', classes ];
     if (configuration['verbose']) {
       print("# $dartcPath ${Strings.join(args, ' ')}");
     }
-    Process dartcProcess = new Process(dartcPath, args);
+    Process dartcProcess = new Process.start(dartcPath, args);
     dartcProcess.exitHandler = (int exitCode) {
       combineFiles(filename, stubsPath, onGenerated);
     };
-    dartcProcess.start();
   }
 
   void processFile(String filename) {
     // Only run the tests that match the pattern.
     RegExp pattern = configuration['selectors'][suiteName];
     if (!pattern.hasMatch(filename)) return;
     var optionsFromFile = optionsFromFile(filename);
     Function createTestCase = makeTestCaseCreator(optionsFromFile);
 
     if (filename.endsWith("-generatedTest.dart")) {
       if (dartcPath == null) {
         createTestCase(filename, optionsFromFile['isNegative']);
       }
     } else if (filename.endsWith("Test.dart")) {
       if (dartcPath != null) {
         String isolateStubsOptions = optionsFromFile['isolateStubs'];
         List<String> splitIsolateStubsOptions = isolateStubsOptions.split(':');
         Expect.equals(2, splitIsolateStubsOptions.length);
         String interfaceFile = splitIsolateStubsOptions[0];
         String classes = splitIsolateStubsOptions[1];
         generateTestCase(filename, interfaceFile, classes, (String filename) {
           createTestCase(filename, optionsFromFile['isNegative']);
           testGeneratorDone();
         });
       }
     }
   }
 }