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

lib/compiler/implementation/lib/io.dart

Index: lib/compiler/implementation/lib/io.dart
diff --git a/lib/compiler/implementation/lib/io.dart b/lib/compiler/implementation/lib/io.dart
index 040925dfa298101ae82c33d38cb8a68cbdc5e618..523306255c394069275324f4b8ad4bba28f3207f 100644
--- a/lib/compiler/implementation/lib/io.dart
+++ b/lib/compiler/implementation/lib/io.dart
@@ -92,19 +92,21 @@ class _Directory {
   }
 }
 
+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);
   }
 }