Add temporary directory for dartc compilation of tests.

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;
 
   StubGeneratorTestSuite(Map configuration)
       : super(configuration,
               "stub-generator",
               "tests/stub-generator/src",
               ["tests/stub-generator/stub-generator.status"]) {
     try {
       dartcPath = TestUtils.compilerPath(configuration);
     } catch (var e) {
       // ignore
     }
   }
 
+  bool get requiresCleanTemporaryDirectory() => true;
+
   void combineFiles(String filename,
                     String stubsFile,
                     Function onGenerated) {
     File orig = new File(filename);
     File stubs = new File(stubsFile);
     Expect.isTrue(filename.endsWith(".dart"));
     String baseName = filename.substring(0, filename.length - 5);
     String resultPath = '${baseName}-generatedTest.dart';
     File result = new File(resultPath);
     StringInputStream origStream =
@@ skipping 58 matching lines @@
       resultStream.close();
       onGenerated(resultPath);
     };
   }
 
   void generateTestCase(String filename,
                         String interfaceFile,
                         String classes,
                         Function onGenerated) {
     testGeneratorStarted();
-    Directory temp = new Directory('');
-    temp.createTempSync();
+    Directory temp = createOutputDirectory(interfaceFile, '');
+
     File stubsOutFile = new File("${temp.path}/${interfaceFile}");
     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, ' ')}");
@@ skipping 23 matching lines @@
         String interfaceFile = splitIsolateStubsOptions[0];
         String classes = splitIsolateStubsOptions[1];
         generateTestCase(filename, interfaceFile, classes, (String filename) {
           createTestCase(filename, optionsFromFile['isNegative']);
           testGeneratorDone();
         });
       }
     }
   }
 }