Create a common directory of widgets and css.

appengine/chromium_rietveld/new_static/components/cr-hash-observer.html

-<!-- Copyright (c) 2014 The Chromium Authors. All rights reserved.
-Use of this source code is governed by a BSD-style license that can be
-found in the LICENSE file. -->
-
-<!--
-    Use to observe to dynamically observe changes to the hash in the url.
-
-    ex.
-        <cr-hash-observer on-hash-changed="{{ handleHashChange }}"></cr-hash-observer>
--->
-<polymer-element name="cr-hash-observer">
-    <template>
-        <style>
-            :host { display: none; }
-        </style>
-    </template>
-    <script>
-    (function() {
-        var instances = [];
-
-        Polymer("cr-hash-observer", {
-            attached: function() {
-                instances.push(this);
-            },
-            detached: function() {
-                var i = instances.indexOf(this);
-                if (i >= 0)
-                    instances.splice(i, 1);
-            },
-        });
-
-        var currentHash = "";
-        function notifyInstancesIfNeeded() {
-            if (window.location.hash == currentHash)
-                return;
-            currentHash = window.location.hash;
-            instances.forEach(function(instance) {
-                instance.asyncFire("hash-changed");
-            });
-        }
-
-        function handleHashChange() {
-            setTimeout(notifyInstancesIfNeeded);
-        }
-
-        document.addEventListener("navigate", handleHashChange);
-        window.addEventListener("hashchange", handleHashChange);
-    })();
-    </script>
-</polymer-element>