When attempting to navigate to a page for an isolate that doesn't exist, offer to

runtime/observatory/observatory_sources.gypi

 # 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.
 
 # This file contains all dart, css, and html sources for Observatory.
 {
   'sources': [
     'lib/app.dart',
     'lib/cli.dart',
     'lib/cpu_profile.dart',
@@ skipping 65 matching lines @@
     'lib/src/elements/heap_profile.dart',
     'lib/src/elements/heap_profile.html',
     'lib/src/elements/inbound_reference.dart',
     'lib/src/elements/inbound_reference.html',
     'lib/src/elements/instance_ref.dart',
     'lib/src/elements/instance_ref.html',
     'lib/src/elements/instance_view.dart',
     'lib/src/elements/instance_view.html',
     'lib/src/elements/io_view.dart',
     'lib/src/elements/io_view.html',
+    'lib/src/elements/isolate_reconnect.dart',
+    'lib/src/elements/isolate_reconnect.html',
     'lib/src/elements/isolate_ref.dart',
     'lib/src/elements/isolate_ref.html',
     'lib/src/elements/isolate_summary.dart',
     'lib/src/elements/isolate_summary.html',
     'lib/src/elements/isolate_view.dart',
     'lib/src/elements/isolate_view.html',
     'lib/src/elements/json_view.dart',
     'lib/src/elements/json_view.html',
     'lib/src/elements/library_ref.dart',
     'lib/src/elements/library_ref.html',
@@ skipping 37 matching lines @@
     'lib/src/elements/img/chromium_icon.png',
     'lib/src/elements/img/dart_icon.png',
     'lib/src/elements/img/isolate_icon.png',
     'lib/src/service/object.dart',
     'lib/tracer.dart',
     'lib/utils.dart',
     'web/index.html',
     'web/main.dart',
     'web/favicon.ico',
   ],
-}
+}