Drop support for old SDK and shelf versions.

lib/src/runner/browser/server.dart

 // Copyright (c) 2015, 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.
 
 library test.runner.browser.server;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 134 matching lines @@
 
   /// Returns a handler that serves the contents of the "packages/" directory
   /// for any URL that contains "packages/".
   ///
   /// This is a factory so it can wrap a static handler.
   shelf.Handler _createPackagesHandler() {
     var staticHandler =
       createStaticHandler(_config.packageRoot, serveFilesOutsidePath: true);
 
     return (request) {
-      var segments = p.url.split(shelfUrl(request).path);
+      var segments = p.url.split(request.url.path);
 
       for (var i = 0; i < segments.length; i++) {
         if (segments[i] != "packages") continue;
         return staticHandler(
-            shelfChange(request, path: p.url.joinAll(segments.take(i + 1))));
+            request.change(path: p.url.joinAll(segments.take(i + 1))));
       }
 
       return new shelf.Response.notFound("Not found.");
     };
   }
 
   /// A handler that serves wrapper files used to bootstrap tests.
   shelf.Response _wrapperHandler(shelf.Request request) {
-    var path = p.fromUri(shelfUrl(request));
+    var path = p.fromUri(request.url);
 
     if (path.endsWith(".browser_test.dart")) {
       return new shelf.Response.ok('''
 import "package:test/src/runner/browser/iframe_listener.dart";
 
 import "${p.basename(p.withoutExtension(p.withoutExtension(path)))}" as test;
 
 void main() {
   IframeListener.start(() => test.main);
 }
@@ skipping 226 matching lines @@
       await Future.wait(futures);
 
       if (_config.pubServeUrl == null) {
         new Directory(_compiledDir).deleteSync(recursive: true);
       } else {
         _http.close();
       }
     });
   }
 }