Update imports to use package:compiler and package:try.

dart/tests/try/mock_try.dart

 // Copyright (c) 2014, 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:html' show
     DivElement,
     MutationObserver,
     document;
 
-import '../../site/try/src/interaction_manager.dart' show
+import 'package:try/src/interaction_manager.dart' show
     InteractionManager;
 
-import '../../site/try/src/ui.dart' show
+import 'package:try/src/ui.dart' show
     hackDiv,
     mainEditorPane,
     observer;
 
-import '../../site/try/src/user_option.dart' show
+import 'package:try/src/user_option.dart' show
     UserOption;
 
 InteractionManager mockTryDartInteraction() {
   UserOption.storage = {};
 
   InteractionManager interaction = new InteractionManager();
 
   hackDiv = new DivElement();
   mainEditorPane = new DivElement()
       ..style.whiteSpace = 'pre'
       ..contentEditable = 'true';
 
   observer = new MutationObserver(interaction.onMutation);
   observer.observe(
       mainEditorPane, childList: true, characterData: true, subtree: true);
 
   document.body.nodes.addAll([mainEditorPane, hackDiv]);
 
   return interaction;
 }
 
 void clearEditorPaneWithoutNotifications() {
   mainEditorPane.nodes.clear();
   observer.takeRecords();
 }