fix embedder on Windows - fixes #25498

pkg/analyzer/test/utils.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 analyzer.test.utils;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/resolver.dart' show TypeProvider;
 import 'package:path/path.dart' as path;
 import 'package:unittest/unittest.dart';
 
-void initializeTestEnvironment() {
+void initializeTestEnvironment([path.Context context]) {
   groupSep = ' | ';
-  JavaFile.pathContext = path.posix;
+  JavaFile.pathContext = context ?? path.posix;

[danrubel, 2016/01/22 19:26:38]

Ultimately, we need to remove the line above... but it will take a number of
other CLs before we can do that.

 }
 
 /**
  * The type of an assertion which asserts properties of [T]s.
  */
 typedef void Asserter<T>(T type);
 
 /**
  * The type of a function which given an [S], builds an assertion over [T]s.
  */
@@ skipping 267 matching lines @@
   Asserter<DartType> isType(DartType argument) => (DartType t) {
         expect(t, same(argument));
       };
 
   /**
    * Given a type, produce an assertion that a type has the same element.
    */
   Asserter<DartType> sameElement(DartType elementType) =>
       hasElement(elementType.element);
 }