Add optional workingDirectory argument to Process.start.

tests/standalone/src/ProcessWorkingDirectoryTest.dart

Index: tests/standalone/src/ProcessWorkingDirectoryTest.dart
===================================================================
--- tests/standalone/src/ProcessWorkingDirectoryTest.dart	(revision 0)
+++ tests/standalone/src/ProcessWorkingDirectoryTest.dart	(revision 0)
@@ -0,0 +1,68 @@
+// 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.
+//
+// Process working directory test.
+
+#library("ProcessWorkingDirectoryTest");
+#source("ProcessTestUtil.dart");
+
+class ProcessWorkingDirectoryTest {
+  static String get fullTestFilePath() {
+    // Extract full path, since we run processes from another directory.
+    File path = new File(getProcessTestFileName());
+    Expect.isTrue(path.existsSync());
+    return path.fullPathSync();
+  }
+
+  static void testValidDirectory() {
+    Directory directory = new Directory("");
+    directory.createTempSync();
+    Expect.isTrue(directory.existsSync());
+
+    print(fullTestFilePath);
+
+    Process process = new Process.start(fullTestFilePath,
+                                        const ["0", "0", "99", "0"],
+                                        directory.path);
+
+    process.exitHandler = (int exitCode) {
+      Expect.equals(exitCode, 99);
+      process.close();
+      directory.deleteSync();
+    };
+
+    process.errorHandler = (error) {
+      Expect.fail("error running process $error");
+      directory.deleteSync();
+    };
+  }
+
+  static void testInvalidDirectory() {
+    Directory directory = new Directory("");
+    directory.createTempSync();
+    Expect.isTrue(directory.existsSync());
+
+    Process process = new Process.start(fullTestFilePath,
+                                        const ["0", "0", "99", "0"],
+                                        directory.path + "/subPath");
+
+    process.exitHandler = (int exitCode) {
+      Expect.fail("bad process completed");
+      process.close();
+      directory.deleteSync();
+    };
+
+    process.errorHandler = (error) {
+      Expect.isNotNull(error);
+      directory.deleteSync();
+    };
+  }
+}
+
+
+
+main() {
+  ProcessWorkingDirectoryTest.testValidDirectory();
+  ProcessWorkingDirectoryTest.testInvalidDirectory();
+}