pkg/test: Resolve a number of analyzer warnings

lib/src/runner/browser/dartium.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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:async/async.dart';
 import 'package:path/path.dart' as p;
@@ skipping 95 matching lines @@
   /// Returns the Observatory URL for the Dartium executable with the given
   /// [stdout] stream, or `null` if the correct one couldn't be found.
   ///
   /// Dartium prints out three different Observatory URLs when it starts. Only
   /// one of them is connected to the VM instance running the host page, and the
   /// ordering isn't guaranteed, so we need to figure out which one is correct.
   /// We do so by connecting to the VM service via WebSockets and looking for
   /// the Observatory instance that actually contains an isolate, and returning
   /// the corresponding URI.
   static Future<Uri> _getObservatoryUrl(Stream<List<int>> stdout) async {
-    var urlQueue = new StreamQueue<Uri>(lineSplitter.bind(stdout).map((line) {
+    var urlQueue = new StreamQueue<Uri>(transformUtf8ToLines(stdout).map((line) {
       var match = _observatoryRegExp.firstMatch(line);
       return match == null ? null : Uri.parse(match[1]);
     }).where((line) => line != null));
 
     var operations = [
       urlQueue.next,
       urlQueue.next,
       urlQueue.next
     ].map((future) => _checkObservatoryUrl(future));
 
@@ skipping 114 matching lines @@
         // incorrect WebSocket that already closed.
         return null;
       }
     }).catchError((error, stackTrace) {
       if (!completer.isCompleted) completer.completeError(error, stackTrace);
     });
 
     return completer.operation;
   }
 }