Clean up some hints in server code

Change-Id: Ia620cfd7c4cb116ca55ce8a4405820007bc69160
Reviewed-on: https://dart-review.googlesource.com/68740
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analysis_server/test/integration/analysis/get_errors_test.dart b/pkg/analysis_server/test/integration/analysis/get_errors_test.dart
index ee09be3d..5c6b2e0 100644
--- a/pkg/analysis_server/test/integration/analysis/get_errors_test.dart
+++ b/pkg/analysis_server/test/integration/analysis/get_errors_test.dart
@@ -2,8 +2,6 @@
 // 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:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
diff --git a/pkg/analysis_server/test/integration/edit/get_statement_completion_test.dart b/pkg/analysis_server/test/integration/edit/get_statement_completion_test.dart
index 347d0df..8f95a0a 100644
--- a/pkg/analysis_server/test/integration/edit/get_statement_completion_test.dart
+++ b/pkg/analysis_server/test/integration/edit/get_statement_completion_test.dart
@@ -2,8 +2,6 @@
 // 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';
diff --git a/pkg/analysis_server/test/src/computer/outline_computer_test.dart b/pkg/analysis_server/test/src/computer/outline_computer_test.dart
index 1ae9d67..9aa971d 100644
--- a/pkg/analysis_server/test/src/computer/outline_computer_test.dart
+++ b/pkg/analysis_server/test/src/computer/outline_computer_test.dart
@@ -5,7 +5,6 @@
 import 'dart:async';
 
 import 'package:analysis_server/src/computer/computer_outline.dart';
-import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:meta/meta.dart';
@@ -13,7 +12,6 @@
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../abstract_context.dart';
-import '../utilities/flutter_util.dart';
 
 main() {
   defineReflectiveSuite(() {
diff --git a/pkg/analysis_server/test/src/flutter/flutter_correction_test.dart b/pkg/analysis_server/test/src/flutter/flutter_correction_test.dart
index 7e4d5d0..4501d68 100644
--- a/pkg/analysis_server/test/src/flutter/flutter_correction_test.dart
+++ b/pkg/analysis_server/test/src/flutter/flutter_correction_test.dart
@@ -8,7 +8,6 @@
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../abstract_single_unit.dart';
-import '../utilities/flutter_util.dart';
 
 main() {
   defineReflectiveSuite(() {
diff --git a/pkg/analysis_server/test/src/flutter/flutter_outline_computer_test.dart b/pkg/analysis_server/test/src/flutter/flutter_outline_computer_test.dart
index 529b001..e4b62c4 100644
--- a/pkg/analysis_server/test/src/flutter/flutter_outline_computer_test.dart
+++ b/pkg/analysis_server/test/src/flutter/flutter_outline_computer_test.dart
@@ -6,13 +6,11 @@
 
 import 'package:analysis_server/src/flutter/flutter_outline_computer.dart';
 import 'package:analysis_server/src/protocol_server.dart';
-import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../abstract_context.dart';
-import '../utilities/flutter_util.dart';
 
 main() {
   defineReflectiveSuite(() {
diff --git a/pkg/analysis_server/test/src/utilities/flutter_test.dart b/pkg/analysis_server/test/src/utilities/flutter_test.dart
index d9a7bcf..b4a0ef0 100644
--- a/pkg/analysis_server/test/src/utilities/flutter_test.dart
+++ b/pkg/analysis_server/test/src/utilities/flutter_test.dart
@@ -4,12 +4,10 @@
 
 import 'package:analysis_server/src/utilities/flutter.dart';
 import 'package:analyzer/dart/ast/ast.dart';
-import 'package:analyzer/file_system/file_system.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../abstract_single_unit.dart';
-import 'flutter_util.dart';
 
 main() {
   defineReflectiveSuite(() {