Merge the dart:uri library into dart:core and update the Uri class

sdk/lib/_internal/pub/test/oauth2/utils.dart

Index: sdk/lib/_internal/pub/test/oauth2/utils.dart
diff --git a/sdk/lib/_internal/pub/test/oauth2/utils.dart b/sdk/lib/_internal/pub/test/oauth2/utils.dart
index fa3ce9881067e11c5b0acb5118d21a815eeedce2..7544506348d9e2119d61e0048997f6b7fce7722d 100644
--- a/sdk/lib/_internal/pub/test/oauth2/utils.dart
+++ b/sdk/lib/_internal/pub/test/oauth2/utils.dart
@@ -6,7 +6,6 @@ library oauth2.utils;
 
 import 'dart:io';
 import 'dart:json' as json;
-import 'dart:uri';
 
 import 'package:http/http.dart' as http;
 import 'package:scheduled_test/scheduled_process.dart';
@@ -27,7 +26,7 @@ void authorizePub(ScheduledProcess pub, ScheduledServer server,
         .firstMatch(line);
     expect(match, isNotNull);
 
-    var redirectUrl = Uri.parse(decodeUriComponent(match.group(1)));
+    var redirectUrl = Uri.parse(Uri.decodeComponent(match.group(1)));
     redirectUrl = addQueryParameters(redirectUrl, {'code': 'access code'});
     return (new http.Request('GET', redirectUrl)..followRedirects = false)
       .send();