Add breakpoints and single-stepping to Observatory.

runtime/bin/vmservice/client/lib/src/elements/nav_bar.dart

 // Copyright (c) 2013, 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 nav_bar_element;
 
+import 'dart:async';
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
 
 
 @CustomTag('nav-bar')
 class NavBarElement extends ObservatoryElement {
   @published bool pad = true;
 
@@ skipping 104 matching lines @@
   @published ObservableList<ServiceEvent> events;
   
   NavNotifyElement.created() : super.created();
 }
 
 @CustomTag('nav-notify-item')
 class NavNotifyItemElement extends ObservatoryElement {
   @published ObservableList<ServiceEvent> events;
   @published ServiceEvent event;
   
+  Future clearBreakpoint(_) {
+    return event.isolate.clearBreakpoint(event.breakpoint);
+  }
+  Future resume(_) {
+    app.removePauseEvents(event.isolate);
+    return event.isolate.resume();
+  }
+  Future stepInto(_) {
+    app.removePauseEvents(event.isolate);
+    return event.isolate.stepInto();
+  }
+  Future stepOver(_) {
+    app.removePauseEvents(event.isolate);
+    return event.isolate.stepOver();
+  }
+  Future stepOut(_) {
+    app.removePauseEvents(event.isolate);
+    return event.isolate.stepOut();
+  }
+
   void closeItem(MouseEvent e, var detail, Element target) {
     events.remove(event);
   }
 
   NavNotifyItemElement.created() : super.created();
 }