Add in OAuth authentication to Isolate Polymer UI

appengine/swarming/ui/res/imp/common/swarming-app.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <swarming-app>
 
   <swarming-app> is meant to be used in top level elements to provide the header
       toolbar and authentication.
 
   It contains the definition of the following style modules:
 
     swarming-app-style
 
   <style include="shared-style"> contains styles to be shared among all
       apps, such as colors.
 
   Properties:
     busy: Boolean, If the busy spinner should be active.
     client_id: String, Oauth 2.0 client id.  It will be set by server-side
         template evaluation.
     name: String, the name of the app to be displayed.
 
     auth_headers: Object, Use this as an argument to sk.request to set oauth2 headers.
     permissions: Object, {String:Boolean} of permissions to perform various
         behaviors, such as terminate_bot.
-    server_details: Object, containing mutliple Strings including:
+    server_details: Object, containing multiple Strings including:
         server_version: what git revision the server is using.
         bot_version: A hash of the bot code being distributed. Isn't associated
             with any git revisions
     signed_in: Boolean, if the user is signed in.
   Methods:
     None.
 
   Events:
     None.
 -->
 
 <link rel="import" href="/res/imp/bower_components/app-layout/app-layout.html">
 <link rel="import" href="/res/imp/bower_components/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="/res/imp/bower_components/iron-icons/iron-icons.html">
 <link rel="import" href="/res/imp/bower_components/iron-media-query/iron-media-query.html">
 <link rel="import" href="/res/imp/bower_components/paper-fab/paper-fab.html">
 <link rel="import" href="/res/imp/bower_components/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="/res/imp/bower_components/paper-item/paper-item.html">
 <link rel="import" href="/res/imp/bower_components/paper-menu/paper-menu.html">
 <link rel="import" href="/res/imp/bower_components/paper-spinner/paper-spinner-lite.html">
 
-<link rel="import" href="auth-signin.html">
+<link rel="import" href="/res/imp/shared/auth-signin.html">
+<link rel="import" href="/res/imp/shared/error-toast.html">
+
 <link rel="import" href="common-behavior.html">
-<link rel="import" href="error-toast.html">
 
 <dom-module id="swarming-app">
   <template>
     <style include="iron-flex">
       :host {
         position: absolute;
         top: 0;
         bottom: 0;
         left: 0;
         right: 0;
@@ skipping 298 matching lines @@
         border: none;
         line-height: 20px;
         vertical-align: middle;
       }
 
       select {
         overflow-y: auto;
       }
   </style>
 </dom-module>