Revert "Build Observatory with runtime"

runtime/observatory/lib/src/elements/curly_block.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 curly_block_element;
-
-import 'package:polymer/polymer.dart';
-
-@CustomTag('curly-block')
-class CurlyBlockElement extends PolymerElement {
-  CurlyBlockElement.created() : super.created();
-
-  @observable bool expanded = false;
-  @observable bool busy = false;
-  @published var callback = null;
-  @published bool expand = false;
-
-  void expandChanged(oldValue) {
-    expanded = expand;
-  }
-
-  void doneCallback() {
-    expanded = !expanded;
-    busy = false;
-  }
-
-  void toggleExpand(var a, var b, var c) {
-    assert(callback == null || expand == false);
-    if (busy) {
-      return;
-    }
-    if (callback != null) {
-      busy = true;
-      callback(!expanded, doneCallback);
-    } else {
-      expanded = !expanded;
-    }
-  }
-}