LogDog: Update web code, stream/query with auth.

web/inc/auth/auth-signin.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.
 -->
 
 <link rel="import" href="../bower_components/polymer/polymer.html">
 <link rel="import"
     href="../bower_components/google-signin/google-signin-aware.html">
 
 <!--
   The `auth-signin` element displays sign-in/sign-out button, user email and
   avatar.
 -->
 <dom-module id="auth-signin">
   <template>
     <style>
       #avatar {
         border-radius: 5px;
       }
       #signinContainer {
         margin-top: 14px;
       }
     </style>
 
     <google-signin-aware id="aware"
-      client-id="[[clientId]]"
       scopes="email"
       on-google-signin-aware-success="_onSignin"
       on-google-signin-aware-signed-out="_onSignout"
     ></google-signin-aware>
 
     <template is="dom-if" if="[[!signedIn]]">
       <div id="signinContainer">
         <a on-tap="signIn" href="#">Sign in</a>
       </div>
     </template>
@@ skipping 14 matching lines @@
       properties: {
         signedIn: {
           type: Boolean,
           readOnly: true,
           value: false
         },
 
         profile: {
           type: Object,
           readOnly: true
+        },
+
+        clientId: {
+          type: String,
+          notify: true,
+          observer: '_clientIdChanged',
+        },
+      },
+
+      created: function() {
+        this._attached = false;
+        this._lastPushedClientId = null;
+      },
+
+      attached: function() {
+        this._attached = true;
+        this._pushClientId();
+      },
+
+      _clientIdChanged: function() {
+        this._pushClientId();
+      },
+
+      _pushClientId: function() {
+        // Set the client ID here explicitly rather than data-binding. If this
+        // page is loaded in the background, the "auth-signin-aware" AuthEngine
+        // will sign in before the <augh-signin-aware> elements actually attach.
+        // Consequently, they will never receive the sign-in success/fail event.
+        //
+        // By delaying the Client ID setting until the elements have all been
+        // attached, we ensure that they all receive the event as intended.
+        if (this._attached && (this.clientId != this._lastPushedClientId)) {
+          this.$.aware.clientId = this.clientId;
+          this._lastPushedClientId = this.clientId;
         }
       },
 
       _onSignin: function(e) {
         this._setSignedIn(true);
         var user = gapi.auth2.getAuthInstance().currentUser.get();
         var profile = user.getBasicProfile();
         this._setProfile({
           email: profile.getEmail(),
           imageUrl: profile.getImageUrl()
         });
       },
 
       _onSignout: function(e) {
         this._setSignedIn(false);
         this._setProfile(null);
       },
 
       signIn: function() {
         this.$.aware.signIn();
       },
 
       signOut: function() {
         this.$.aware.signOut();
       }
     });
   </script>
 </dom-module>