anchor.diff:    ModuleManager modules = new ModuleManager();
   
     Playground() {
  -    TabController controller = new TabController();
  +    sourceTabController = new TabController();
       for (String name in ['dart', 'html', 'css']) {
  -      controller.registerTab(new TabElement(querySelector('#${name}tab'),
  +      sourceTabController.registerTab(new TabElement(querySelector('#${name}tab'),
             name: name, onSelect: () {
           Element issuesElement = querySelector('#issues');
  -        if (name != "dart") {
  -          issuesElement.style.display = "none";
  -        } else {
  -          issuesElement.style.display = "block";
  -        }
  +        issuesElement.style.display = name == 'dart' ? 'block' : 'none';
           ga.sendEvent('edit', name);
           _context.switchTo(name);
         }));
  
positive.code:     });
    }
  
    /// Switch to the console or html results tab depending on whether the sample
    /// has html content or not.
    void _switchOutputTab(String html, String dart) {
      if (html.trim().isEmpty && !dart.contains("'dart:html'")
          && !dart.contains('"dart:html"')) {
        outputTabController.selectTab("console");
      } else {
        outputTabController.selectTab("result");
      }
    }
    
    Future<String> _createSummary() {
      SourceRequest input = new SourceRequest()..source = _context.dartSource;
      return dartServices
  
negative.code:       ga.sendTiming('action-perf', "compilation-e2e",
            compilationTimer.elapsedMilliseconds);
  
        _autoSwitchOutputTab();
  
        return executionService.execute(
            _context.htmlSource, _context.cssSource, response.result);
  