Removed Polymer from Observatory deps

packages/polymer/lib/src/property_accessor.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.
-
-/// Code for property accessors from declaration/properties.js
-part of polymer;
-
-// Dart note: this matches the property defined by createPropertyAccessor in
-// polymer-dev/src/declarations/properties.js. Unlike Javascript, we can't
-// override the original property, so we instead ask users to write properties
-// using this pattern:
-//
-//     class Foo extends PolymerElement {
-//       ...
-//       @published
-//       get foo => readValue(#foo);
-//       set foo(v) { writeValue(#foo, v); }
-//
-// and internally readValue/writeValue use an instance of this type to
-// implement the semantics in createPropertyAccessor.
-class _PropertyAccessor<T> {
-  // Name of the property, in order to properly fire change notification events.
-  final Symbol _name;
-
-  /// The underlying value of the property.
-  T _value;
-
-  // Polymer element that contains this property, where change notifications are
-  // expected to be fired from.
-  final Polymer _target;
-
-  /// Non-null when the property is bound.
-  Bindable bindable;
-
-  _PropertyAccessor(this._name, this._target, this._value);
-
-  /// Updates the underlyling value and fires the expected notifications.
-  void updateValue(T newValue) {
-    var oldValue = _value;
-    _value = _target.notifyPropertyChange(_name, oldValue, newValue);
-    _target.emitPropertyChangeRecord(_name, newValue, oldValue);
-  }
-
-  /// The current value of the property. If the property is bound, reading this
-  /// property ensures that the changes are first propagated in order to return
-  /// the latest value. Similarly, when setting this property the binding (if
-  /// any) will be updated too.
-  T get value {
-    if (bindable != null) bindable.deliver();
-    return _value;
-  }
-
-  set value(T newValue) {
-    // Dart Note: The js side makes computed properties read only, and bails
-    // out right here for them (ignoreWrites). For us they are automatically
-    // read only unless you define a setter for them, so we left that out.
-    if (bindable != null) {
-      bindable.value = newValue;
-    } else {
-      updateValue(newValue);
-    }
-  }
-
-  toString() {
-    var name = smoke.symbolToName(_name);
-    var hasBinding = bindable == null ? '(no-binding)' : '(with-binding)';
-    return "[$runtimeType: $_target.$name: $_value $hasBinding]";
-  }
-}