Removed Polymer from Observatory deps

packages/polymer_expressions/example/example.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.
-
-import 'dart:html';
-
-import 'package:polymer_expressions/polymer_expressions.dart';
-import 'package:template_binding/template_binding.dart' show templateBind;
-
-// We use mirrors for illustration purposes, but ideally we would generate a
-// static configuration with smoke/static.dart.
-import 'package:smoke/mirrors.dart';
-
-// Since we use smoke/mirrors, we need to preserve symbols used in the template.
-// This includes String.startsWith, List.take, and Person.
-@MirrorsUsed(targets: const [String, List, Person])
-import 'dart:mirrors';
-
-import 'person.dart';
-
-main() {
-  useMirrors();
-  var john = new Person('John', 'Messerly', ['A', 'B', 'C']);
-  var justin = new Person('Justin', 'Fagnani', ['D', 'E', 'F']);
-  var globals = {
-    'uppercase': (String v) => v.toUpperCase(),
-    'people': [john, justin],
-  };
-
-  templateBind(querySelector('#test'))
-      ..bindingDelegate = new PolymerExpressions(globals: globals)
-      ..model = john;
-
-  templateBind(querySelector('#test2')).model = john;
-}