Use words please.

runtime/observatory/tests/service/steal_breakpoint_test.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.
 // VMOptions=--compile-all --error_on_bad_type --error_on_bad_override --steal-breakpoints
 
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
 import 'test_helper.dart';
 import 'dart:async';
 
 int counter = 0;
 
 void periodicTask(_) {
   counter++;  // Line 14.  We set our breakpoint here.
   if (counter % 1000 == 0) {
     print('counter = $counter');
   }
 }
 
 void startTimer() {
   new Timer.periodic(const Duration(milliseconds:10), periodicTask);
 }
 
 var tests = [
 
 // Add a breakpoint and wait for it to be reached.
 (Isolate isolate) async {
-  await isolate.rootLib.load();
+  await isolate.rootLibrary.load();
 
   // Set up a listener to wait for breakpoint events.
   Completer completer = new Completer();
   var subscription;
   subscription = isolate.vm.events.stream.listen((ServiceEvent event) {
     if (event.eventType == ServiceEvent.kPauseBreakpoint) {
       print('Isolate paused at breakpoint');
       subscription.cancel();
       completer.complete();
     }
   });
 
   // Add the breakpoint.
-  var script = isolate.rootLib.scripts[0];
+  var script = isolate.rootLibrary.scripts[0];
   var result = await isolate.addBreakpoint(script, 14);
   expect(result is Breakpoint, isTrue);
 
   await completer.future;  // Wait for breakpoint event to fire.
 },
 
 // We are at the breakpoint on line 14.
 (Isolate isolate) async {
   ServiceMap stack = await isolate.getStack();
   expect(stack.type, equals('Stack'));
@@ skipping 16 matching lines @@
       completer.complete();
     }
   });
   isolate.resume();
   await completer.future;
 },
 
 ];
 
 main(args) => runIsolateTests(args, tests, testeeBefore: startTimer);