Update some of the fixes to use ChangeBuilder

pkg/analysis_server/test/integration/edit/get_fixes_test.dart

 // Copyright (c) 2017, 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.
 
+import 'dart:async';
+
 import 'package:analysis_server/protocol/protocol_generated.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../support/integration_tests.dart';
 
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(GetFixesTest);
@@ skipping 25 matching lines @@
     // apply the fix, expect that the new code has no errors
     SourceChange change = fix.fixes.singleWhere(
         (SourceChange change) => change.message.startsWith('Import '));
     expect(change.edits, hasLength(1));
     expect(change.edits.first.edits, hasLength(1));
     SourceEdit edit = change.edits.first.edits.first;
     text = text.replaceRange(edit.offset, edit.end, edit.replacement);
     writeFile(pathname, text);
 
     await analysisFinished;
+    // The errors (at least sometimes) don't get sent until after analysis has
+    // completed. Wait long enough to see whether new errors are reported.
+    await new Future.delayed(new Duration(milliseconds: 1000));
     expect(currentAnalysisErrors[pathname], isEmpty);
   }
 
   test_no_fixes() async {
     String pathname = sourcePath('test.dart');
     String text = r'''
 import 'dart:async';
 
 Future f;
 ''';
     writeFile(pathname, text);
     standardAnalysisSetup();
 
     EditGetFixesResult result =
         await sendEditGetFixes(pathname, text.indexOf('Future f'));
     expect(result.fixes, isEmpty);
   }
 }