Use the right name for the OldWebSocketApi constructor.

sdk/lib/_internal/pub/lib/src/barback/old_web_socket_api.dart

Index: sdk/lib/_internal/pub/lib/src/barback/old_web_socket_api.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/web_socket_api.dart b/sdk/lib/_internal/pub/lib/src/barback/old_web_socket_api.dart
similarity index 98%
copy from sdk/lib/_internal/pub/lib/src/barback/web_socket_api.dart
copy to sdk/lib/_internal/pub/lib/src/barback/old_web_socket_api.dart
index eeb804f98f6947641fb86e6c20dbf9f36db893b3..4790582c1476527bf4b463f2f063f9c68121ff9d 100644
--- a/sdk/lib/_internal/pub/lib/src/barback/web_socket_api.dart
+++ b/sdk/lib/_internal/pub/lib/src/barback/old_web_socket_api.dart
@@ -2,21 +2,20 @@
 // 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 pub.barback.web_socket_api;
+// TODO(nweiz): Remove this when the Editor is using the admin server port. See
+// issue 17640.
+library pub.barback.old_web_socket_api;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
-import 'package:barback/barback.dart';
 import 'package:path/path.dart' as path;
 import 'package:stack_trace/stack_trace.dart';
 
-import '../log.dart' as log;
 import '../utils.dart';
 import 'build_environment.dart';
 
-import '../log.dart' as log;
 
 /// Implements the [WebSocket] API for communicating with a running pub serve
 /// process, mainly for use by the Editor.
@@ -53,13 +52,13 @@ import '../log.dart' as log;
 /// category of error.
 ///
 /// No successful response map will contain a key named "error".
-class WebSocketApi {
+class OldWebSocketApi {
   final WebSocket _socket;
   final BuildEnvironment _environment;
 
   Map<String, _CommandHandler> _commands;
 
-  WebSocketApi(this._socket, this._environment) {
+  OldWebSocketApi(this._socket, this._environment) {
     _commands = {
       "urlToAssetId": _urlToAssetId,
       "pathToUrls": _pathToUrls,