Implement 'edit.getRefactoring' for rename refactoring.

pkg/analysis_server/test/services/refactoring/rename_library_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.services.refactoring.rename_library;
 
 import 'package:analysis_server/src/protocol2.dart';
 import 'package:analysis_testing/reflective_tests.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
@@ skipping 12 matching lines @@
 class RenameLibraryTest extends RenameRefactoringTest {
   void test_checkNewName() {
     indexTestUnit('''
 library my.app;
 ''');
     _createRenameRefactoring();
     // null
     refactoring.newName = null;
     assertRefactoringStatus(
         refactoring.checkNewName(),
-        RefactoringProblemSeverity.ERROR,
+        RefactoringProblemSeverity.FATAL,
         expectedMessage: "Library name must not be null.");
     // empty
     refactoring.newName = '';
     assertRefactoringStatus(
         refactoring.checkNewName(),
-        RefactoringProblemSeverity.ERROR,
+        RefactoringProblemSeverity.FATAL,
         expectedMessage: "Library name must not be blank.");
     // same name
     refactoring.newName = 'my.app';
     assertRefactoringStatus(
         refactoring.checkNewName(),
         RefactoringProblemSeverity.FATAL,
         expectedMessage: "The new name must be different than the current name.");
   }
 
   test_createChange() {
@@ skipping 19 matching lines @@
       assertFileChangeResult('/part.dart', '''
 part of the.new.name;
 ''');
     });
   }
 
   void _createRenameRefactoring() {
     createRenameRefactoringForElement(testUnitElement.library);
   }
 }