Fix the test on Windows.

pkg/analyzer/test/generated/compile_time_error_code_test.dart

 // Copyright (c) 2014, 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.generated.compile_time_error_code_test;
 
 import 'dart:async';
 
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/error/codes.dart';
@@ skipping 6139 matching lines @@
     assertErrors(source, [CompileTimeErrorCode.URI_DOES_NOT_EXIST]);
   }
 
   test_uriDoesNotExist_import_appears_after_deleting_target() async {
     Source test = addSource("import 'target.dart';");
     Source target = addNamedSource("/target.dart", "");
     await computeAnalysisResult(test);
     assertErrors(test, [HintCode.UNUSED_IMPORT]);
 
     // Remove the overlay in the same way as AnalysisServer.
-    resourceProvider.deleteFile('/target.dart');
+    resourceProvider.deleteFile(resourceProvider.convertPath('/target.dart'));
     analysisContext2.setContents(target, null);
     ChangeSet changeSet = new ChangeSet()..removedSource(target);
     analysisContext2.applyChanges(changeSet);
 
     await computeAnalysisResult(test);
     assertErrors(test, [CompileTimeErrorCode.URI_DOES_NOT_EXIST]);
   }
 
   test_uriDoesNotExist_import_disappears_when_fixed() async {
     Source source = addSource("import 'target.dart';");
@@ skipping 351 matching lines @@
   test_uriDoesNotExist_import_disappears_when_fixed() {
     return super.test_uriDoesNotExist_import_disappears_when_fixed();
   }
 
   @failingTest
   @override
   test_uriWithInterpolation_nonConstant() {
     return super.test_uriWithInterpolation_nonConstant();
   }
 }