Always use POSIX path in Entry.load in scheduled_test.

pkg/scheduled_test/lib/src/descriptor/entry.dart

 // Copyright (c) 2013, 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.
 
 library descriptor.entry;
 
 import 'dart:async';
 
 import '../utils.dart';
 import 'utils.dart';
@@ skipping 21 matching lines @@
   /// described by [this]. Returns a [Future] that completes to `null` if the
   /// entry is valid, or throws an error if it failed.
   ///
   /// [parent] defaults to [defaultRoot].
   Future validate([String parent]);
 
   /// Treats [this] as an in-memory filesystem and returns a stream of the
   /// contents of the child entry located at [path]. This only works if [this]
   /// is a directory entry. This operation is not [schedule]d.
   ///
+  /// This method uses POSIX paths regardless of the underlying operating
+  /// system.
+  ///
   /// All errors in loading the file will be passed through the returned
   /// [Stream].
   Stream<List<int>> load(String pathToLoad) => errorStream("Can't load "
       "'$pathToLoad' from within $nameDescription: not a directory.");
 
   /// Returns the contents of [this] as a stream. This only works if [this] is a
   /// file entry. This operation is not [schedule]d.
   ///
   /// All errors in loading the file will be passed through the returned
   /// [Stream].
   Stream<List<int>> read();
 
   /// Asserts that the name of the descriptor is a [String] and returns it.
   String get stringName {
     if (name is String) return name;
     throw 'Pattern $nameDescription must be a string.';
   }
 
   /// Returns a human-readable description of [name], for error reporting. For
   /// string names, this will just be the name in quotes; for regular
   /// expressions, it will use JavaScript-style `/.../` notation.
   String get nameDescription => describePattern(name);
 
   /// Returns a detailed tree-style description of [this].
   String describe();
 }