Removed Polymer from Observatory deps

packages/polymer/lib/src/initializers.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.
-part of polymer;
-
-/// Automatically registers a polymer element.
-class CustomTag implements Initializer<Type> {
-  final String tagName;
-  const CustomTag(this.tagName);
-
-  @override
-  initialize(Type t) => Polymer.register(tagName, t);
-}
-
-/// Calls a zero argument [Function] after [Polymer.onReady] completes.
-typedef dynamic _ZeroArg();
-class _WhenPolymerReady implements Initializer<_ZeroArg> {
-  const _WhenPolymerReady();
-
-  @override
-  void initialize(_ZeroArg f) {
-    Polymer.onReady.then((_) => f());
-  }
-}
-
-const whenPolymerReady = const _WhenPolymerReady();
-