Build Observatory as part of runtime

runtime/observatory/lib/src/elements/script_inset.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 script_inset_element;
 
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
@@ skipping 128 matching lines @@
     } else {
       // Existing breakpoint.  Remove it.
       line.script.isolate.clearBreakpoint(line.bpt).then((_) {
           busy = false;
       });
     }
   }
 
   BreakpointToggleElement.created() : super.created();
 }