Provide URLs for assets from lib/ and asset/ in pub's websocket API.

sdk/lib/_internal/pub/lib/src/utils.dart

 // Copyright (c) 2012, 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.
 
 /// Generic utility functions. Stuff that should possibly be in core.
 library pub.utils;
 
 import 'dart:async';
 import "dart:collection";
 import "dart:convert";
@@ skipping 215 matching lines @@
   for (var metacharacter in r"\^$.*+?()[]{}|".split("")) {
     string = string.replaceAll(metacharacter, "\\$metacharacter");
   }
 
   return string;
 }
 
 /// Creates a URL string for [address]:[port].
 ///
 /// Handles properly formatting IPv6 addresses.
-String baseUrlForAddress(InternetAddress address, int port) {
+Uri baseUrlForAddress(InternetAddress address, int port) {
   // IPv6 addresses in URLs need to be enclosed in square brackets to avoid
   // URL ambiguity with the ":" in the address.
   if (address.type == InternetAddressType.IP_V6) {
-    return "http://[${address.address}]:$port";
+    return new Uri(scheme: "http", host: "[${address.address}]", port: port);
   }
 
-  return "http://${address.address}:$port";
+  return new Uri(scheme: "http", host: address.address, port: port);
 }
 
 /// Flattens nested lists inside an iterable into a single list containing only
 /// non-list elements.
 List flatten(Iterable nested) {
   var result = [];
   helper(list) {
     for (var element in list) {
       if (element is List) {
         helper(element);
@@ skipping 665 matching lines @@
     error is AnalyzerErrorGroup ||
     error is IsolateSpawnException ||
     error is FileSystemException ||
     error is HttpException ||
     error is HttpException ||
     error is OSError ||
     error is ProcessException ||
     error is SocketException ||
     error is WebSocketException;
 }