Fix operator== and hashCode for File and Folder objects.

pkg/analysis_server/test/physical_resource_provider_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 test.physical.resource.provider;
 
 import 'dart:async';
 import 'dart:io' as io;
 
 import 'package:analysis_server/src/resource.dart';
@@ skipping 132 matching lines @@
             new io.File(path).writeAsStringSync('contents');
             expect(file.exists, isTrue);
           });
         });
 
         test('fullName', () {
           expect(file.path, path);
         });
 
         test('hashCode', () {
-          file.hashCode;
+          new io.File(path).writeAsStringSync('contents');
+          File file2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(file.hashCode, equals(file2.hashCode));
+        });
+
+        test('equality', () {
+          new io.File(path).writeAsStringSync('contents');
+          File file2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(file == file2, isTrue);
         });
 
         test('shortName', () {
           expect(file.shortName, 'file.txt');
         });
 
         test('toString', () {
           expect(file.toString(), path);
         });
 
         test('parent', () {
           Resource parent = file.parent;
           expect(parent, new isInstanceOf<Folder>());
           expect(parent.path, equals(tempPath));
         });
       });
 
       group('Folder', () {
         String path;
         Folder folder;
 
         setUp(() {
           path = join(tempPath, 'folder');
           new io.Directory(path).createSync();
           folder = PhysicalResourceProvider.INSTANCE.getResource(path);
         });
 
+        test('hashCode', () {
+          Folder folder2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(folder.hashCode, equals(folder2.hashCode));
+        });
+
+        test('equality', () {
+          Folder folder2 = PhysicalResourceProvider.INSTANCE.getResource(path);
+          expect(folder == folder2, isTrue);
+        });
+
         group('getChild', () {
           test('does not exist', () {
             var child = folder.getChild('no-such-resource');
             expect(child, isNotNull);
             expect(child.exists, isFalse);
           });
 
           test('file', () {
             new io.File(join(path, 'myFile')).createSync();
             var child = folder.getChild('myFile');
@@ skipping 62 matching lines @@
           expect(folder.canonicalizePath(join('.', 'baz')), equals(join(path, 'baz')));
           expect(folder.canonicalizePath(join(path2, '.', 'baz')), equals(join(path2, 'baz')));
         });
       });
     });
 }
 
 var _isFile = new isInstanceOf<File>();
 var _isFolder = new isInstanceOf<Folder>();
 var _isMemoryResourceException = new isInstanceOf<MemoryResourceException>();