Fix for renaming import without an import prefix.

pkg/analysis_server/test/edit/refactoring_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.edit.refactoring;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/edit/edit_domain.dart';
 import 'package:analysis_server/src/protocol.dart';
@@ skipping 1240 matching lines @@
       return sendRenameRequest('test() {}', 'newName');
     }, '''
 newName() {}
 main() {
   newName();
   print(newName);
 }
 ''');
   }
 
+  test_importPrefix_add() {
+    addTestFile('''
+import 'dart:math';
+import 'dart:async';
+main() {
+  Random r;
+  Future f;
+}
+''');
+    return assertSuccessfulRefactoring(() {
+      return sendRenameRequest("import 'dart:async';", 'new_name');
+    }, '''
+import 'dart:math';
+import 'dart:async' as new_name;
+main() {
+  Random r;
+  new_name.Future f;
+}
+''');
+  }
+
+  test_importPrefix_remove() {
+    addTestFile('''
+import 'dart:math' as test;
+import 'dart:async' as test;
+main() {
+  test.Random r;
+  test.Future f;
+}
+''');
+    return assertSuccessfulRefactoring(() {
+      return sendRenameRequest("import 'dart:async' as test;", '');
+    }, '''
+import 'dart:math' as test;
+import 'dart:async';
+main() {
+  test.Random r;
+  Future f;
+}
+''');
+  }
+
   test_init_fatalError_noElement() {
     addTestFile('// nothing to rename');
     return getRefactoringResult(() {
       return sendRenameRequest('// nothing', null);
     }).then((result) {
       assertResultProblemsFatal(
           result.initialProblems,
           'Unable to create a refactoring');
       // ...there is no any change
       expect(result.change, isNull);
@@ skipping 231 matching lines @@
   }
 
   @override
   void setUp() {
     super.setUp();
     server.handlers = [new EditDomainHandler(server),];
     createProject();
     handler = new EditDomainHandler(server);
   }
 }