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

tests/compiler/dart2js/mirrors_test.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.
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 import '../../../sdk/lib/_internal/compiler/implementation/mirrors/mirrors.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/mirrors/mirrors_util.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart';
 import '../../../sdk/lib/_internal/compiler/implementation/filenames.dart'
-       show currentDirectory, nativeToUriPath;
+       show currentDirectory;
 import '../../../sdk/lib/_internal/compiler/implementation/source_file_provider.dart';
 
 import 'dart:io';
 
 final Uri DART_MIRRORS_URI = new Uri(scheme: 'dart', path: 'mirrors');
 
 int count(Iterable iterable) {
   var count = 0;
   for (var element in iterable) {
     count++;
@@ skipping 13 matching lines @@
 DeclarationMirror findMirror(Iterable<DeclarationMirror> list, String name) {
   for (DeclarationMirror mirror in list) {
     if (mirror.simpleName == name) {
       return mirror;
     }
   }
   return null;
 }
 
 main() {
-  Uri scriptUri =
-      currentDirectory.resolve(nativeToUriPath(Platform.script));
+  Uri scriptUri = currentDirectory.resolveUri(Platform.script);
   Uri libUri = scriptUri.resolve('../../../sdk/');
   Uri inputUri = scriptUri.resolve('mirrors_helper.dart');
   var provider = new CompilerSourceFileProvider();
   var diagnosticHandler =
         new FormattingDiagnosticHandler(provider).diagnosticHandler;
   asyncStart();
   var result = analyze([inputUri], libUri, null,
                        provider.readStringFromUri, diagnosticHandler,
                        <String>['--preserve-comments']);
   result.then((MirrorSystem mirrors) {
@@ skipping 969 matching lines @@
   Expect.isTrue(privateFactoryConstructor.isPrivate);
   Expect.isFalse(privateFactoryConstructor.isConstConstructor);
   Expect.isFalse(privateFactoryConstructor.isRedirectingConstructor);
   Expect.isFalse(privateFactoryConstructor.isGenerativeConstructor);
   Expect.isTrue(privateFactoryConstructor.isFactoryConstructor);
 
   var metadata = privateClass.metadata;
   Expect.isNotNull(metadata);
   Expect.equals(0, metadata.length);
 }