delete observe from the repo

pkg/observe/lib/html.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.
-
-// TODO(jmesserly): can we handle this more elegantly?
-// In general, it seems like we want a convenient way to take a Stream plus a
-// getter and convert this into an Observable.
-
-/// Helpers for exposing dart:html as observable data.
-library observe.html;
-
-import 'dart:html';
-
-import 'observe.dart';
-
-/// An observable version of [window.location.hash].
-final ObservableLocationHash windowLocation = new ObservableLocationHash._();
-
-class ObservableLocationHash extends ChangeNotifier {
-  Object _currentHash;
-
-  ObservableLocationHash._() {
-    // listen on changes to #hash in the URL
-    // Note: listen on both popState and hashChange, because IE9 doesn't support
-    // history API. See http://dartbug.com/5483
-    // TODO(jmesserly): only listen to these if someone is listening to our
-    // changes.
-    window.onHashChange.listen(_notifyHashChange);
-    window.onPopState.listen(_notifyHashChange);
-
-    _currentHash = hash;
-  }
-
-  @reflectable String get hash => window.location.hash;
-
-  /// Pushes a new URL state, similar to the affect of clicking a link.
-  /// Has no effect if the [value] already equals [window.location.hash].
-  @reflectable void set hash(String value) {
-    if (value == hash) return;
-
-    window.history.pushState(null, '', value);
-    _notifyHashChange(null);
-  }
-
-  void _notifyHashChange(_) {
-    var oldValue = _currentHash;
-    _currentHash = hash;
-    notifyPropertyChange(#hash, oldValue, _currentHash);
-  }
-}
-
-/// *Deprecated* use [CssClassSet.toggle] instead.
-///
-/// Add or remove CSS class [className] based on the [value].
-@deprecated
-void updateCssClass(Element element, String className, bool value) {
-  if (value == true) {
-    element.classes.add(className);
-  } else {
-    element.classes.remove(className);
-  }
-}
-
-/// *Deprecated* use `class="{{ binding }}"` in your HTML instead. It will also
-/// work on a `<polymer-element>`.
-///
-/// Bind a CSS class to the observable [object] and property [path].
-@deprecated
-PathObserver bindCssClass(Element element, String className,
-    Observable object, String path) {
-
-  callback(value) {
-    updateCssClass(element, className, value);
-  }
-
-  var obs = new PathObserver(object, path);
-  callback(obs.open(callback));
-  return obs;
-}