Revert "Change dart:io Platform.script to return a Uri."

sdk/lib/io/platform.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.
 
 part of dart.io;
 
 /**
  * The [Platform] class exposes details of the machine and operating
  * system.
  */
@@ skipping 62 matching lines @@
   /**
    * Returns the path of the executable used to run the script in this
    * isolate.
    *
    * If the execution environment does not support [executable] an empty
    * string is returned.
    */
   static String get executable => _Platform.executable;
 
   /**
-   * Returns the URI of the script being run in this
+   * Returns the URI (in String form) of the script being run in this
    * isolate. If the URI is relative it is relative to the file URI of
    * the working directory of the VM when it was started.
    *
    * If the executable environment does not support [script] an empty
-   * URI is returned.
+   * string is returned.
    */
-  static Uri get script => _Platform.script;
+  static String get script => _nativeScript;
 
   /**
    * Returns the flags passed to the executable used to run the script in this
    * isolate. These are the command-line flags between the executable name
    * and the script name. Each fetch of executableArguments returns a new
    * List, containing the flags passed to the executable.
    */
   static List<String> get executableArguments => _Platform.executableArguments;
 
   /**
    * Returns the value of the --package-root flag passed to the executable
    * used to run the script in this isolate.  This is the directory in which
    * Dart packages are looked up.
    *
    * If there is no --package-root flag, then the empty string is returned.
    */
   static String get packageRoot => _Platform.packageRoot;
 
   /**
    * Returns the version of the current Dart runtime.
    */
   static String get version => _version;
 }