Bump pkg:web dependency

Use `show` on pkg:web so it's easier to see if usage changes
Tighten constraints on dev dependencies

pkgs/http/CHANGELOG.md

@@ -1,4 +1,6 @@
-## 1.2.2-wip
+## 1.2.2
+
+* Require package `web: '>=0.5.0 <2.0.0'`.
 
 ## 1.2.1
 

pkgs/http/lib/src/browser_client.dart

@@ -5,7 +5,7 @@
 import 'dart:async';
 import 'dart:js_interop';
 
-import 'package:web/web.dart';
+import 'package:web/web.dart' show XMLHttpRequest, XHRGetters;
 
 import 'base_client.dart';
 import 'base_request.dart';

pkgs/http/pubspec.yaml

@@ -1,5 +1,5 @@
 name: http
-version: 1.2.2-wip
+version: 1.2.2
 description: A composable, multi-platform, Future-based API for HTTP requests.
 repository: https://github.com/dart-lang/http/tree/master/pkgs/http
 
@@ -15,13 +15,13 @@ dependencies:
   async: ^2.5.0
   http_parser: ^4.0.0
   meta: ^1.3.0
-  web: ^0.5.0
+  web: '>=0.5.0 <2.0.0'
 
 dev_dependencies:
   dart_flutter_team_lints: ^3.0.0
   fake_async: ^1.2.0
   http_client_conformance_tests:
     path: ../http_client_conformance_tests/
   shelf: ^1.1.0
-  stream_channel: ^2.1.0
-  test: ^1.16.0
+  stream_channel: ^2.1.1
+  test: ^1.21.2

pkgs/http/test/html/utils.dart

@@ -2,7 +2,7 @@
 // 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 'package:web/web.dart';
+import 'package:web/web.dart' show window;
 
 export '../utils.dart';