Revert "Build Observatory with runtime"

runtime/observatory/lib/src/app/settings.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.
-
-part of app;
-
-/// Static settings database.
-class _Settings {
-  static Storage _storage = window.localStorage;
-
-  /// Associated [value] with [key]. [value] must be JSON encodable.
-  static void set(String key, dynamic value) {
-    _storage[key] = JSON.encode(value);
-  }
-
-  /// Get value associated with [key]. Return value will be a JSON encodable
-  /// object.
-  static dynamic get(String key) {
-    var value = _storage[key];
-    if (value == null) {
-      return null;
-    }
-    return JSON.decode(value);
-  }
-}
-
-/// A group of settings each prefixed with group name and a dot.
-class SettingsGroup {
-  /// Group name
-  final String group;
-
-  SettingsGroup(this.group);
-
-  String _fullKey(String key) => '$group.$key';
-
-  void set(String key, dynamic value) {
-    var fullKey = _fullKey(key);
-    _Settings.set(fullKey, value);
-  }
-
-  dynamic get(String key) {
-    var fullKey = _fullKey(key);
-    return _Settings.get(fullKey);
-  }
-}