Change dart:io to use Future for one-shot operations.

lib/compiler/implementation/lib/io.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.
 
 // This is a copy of the VM's dart:io library. This API is not usable
 // when running inside a web browser. Nevertheless, Leg provides a
 // mock version of the dart:io library so that it can statically
 // analyze programs that use dart:io.
 
 // TODO(ahe): Separate API from implementation details.
@@ skipping 74 matching lines @@
 class _Directory {
   factory Directory(arg) {
     throw new UnsupportedOperationException('new Directory($arg)');
   }
 
   factory Directory.current() {
     throw new UnsupportedOperationException('new Directory.current()');
   }
 }
 
+class _DirectoryLister {
+}
+
 class _Process {
-  factory Process.start(String executable,
-                        List<String> arguments,
-                        [ProcessOptions options]) {
-    var msg = 'new Process.start($executable, $arguments, $options)';
+  static Process start(String executable,
+                       List<String> arguments,
+                       [ProcessOptions options]) {
+    var msg = 'Process.start($executable, $arguments, $options)';
     throw new UnsupportedOperationException(msg);
   }
 
-  factory Process.run(String executable,
-                      List<String> arguments,
-                      ProcessOptions options,
-                      void callback(int exit, String out, String err)) {
-    var msg = 'new Process.run($executable, $arguments, $options, $callback)';
+  static Future<ProcessResult> run(String executable,
+                                   List<String> arguments,
+                                   [ProcessOptions options]) {
+    var msg = 'Process.run($executable, $arguments, $options)';
     throw new UnsupportedOperationException(msg);
   }
 }
 
 class _ServerSocket {
   factory ServerSocket(String bindAddress, int port, int backlog) {
     throw new UnsupportedOperationException(
         'new ServerSocket($bindAddress, $port, $backlog)');
   }
 }
@@ skipping 25 matching lines @@
   static void set _eventHandler(_EventHandler e) {
     throw new UnsupportedOperationException('_EventHandler._eventhandler = $e');
   }
 }
 
 final InputStream stdin = null;
 
 final OutputStream stdout = null;
 
 final OutputStream stderr = null;