Sign in Now to GCM, only when user is signed in.

chrome/browser/resources/google_now/background.js

 // Copyright (c) 2013 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 strict';
 
 /**
  * @fileoverview The event page for Google Now for Chrome implementation.
  * The Google Now event page gets Google Now cards from the server and shows
  * them as Chrome notifications.
@@ skipping 1010 matching lines @@
   // We don't clear localStorage since those values are still relevant
   // across Google Now start-stop events.
   chrome.storage.local.clear();
 }
 
 /**
  * Initializes the event page on install or on browser startup.
  */
 function initialize() {
   recordEvent(GoogleNowEvent.EXTENSION_START);
-  // TODO(skare): Reenable, after signin.
-  unregisterFromGcm();
   onStateChange();
 }
 
 /**
  * Starts or stops the main pipeline for polling cards.
  * @param {boolean} shouldPollCardsRequest true to start and
  *     false to stop polling cards.
  */
 function setShouldPollCards(shouldPollCardsRequest) {
   updateCardsAttempts.isRunning(function(currentValue) {
     if (shouldPollCardsRequest != currentValue) {
       console.log('Action Taken setShouldPollCards=' + shouldPollCardsRequest);
       if (shouldPollCardsRequest)
         startPollingCards();
       else
         stopPollingCards();
     } else {
       console.log(
           'Action Ignored setShouldPollCards=' + shouldPollCardsRequest);
     }
   });
 }
 
 /**
- * Starts or stops the optin check.
+ * Starts or stops the optin check and GCM channel to receive optin
+ * notifications.
  * @param {boolean} shouldPollOptInStatus true to start and false to stop
  *     polling the optin status.
  */
 function setShouldPollOptInStatus(shouldPollOptInStatus) {
   optInPollAttempts.isRunning(function(currentValue) {
     if (shouldPollOptInStatus != currentValue) {
       console.log(
           'Action Taken setShouldPollOptInStatus=' + shouldPollOptInStatus);
       if (shouldPollOptInStatus) {
         pollOptedInNoImmediateRecheck();
       } else {
         optInPollAttempts.stop();
       }
     } else {
       console.log(
           'Action Ignored setShouldPollOptInStatus=' + shouldPollOptInStatus);
     }
   });
+
+  if (shouldPollOptInStatus) {
+    registerForGcm();
+  } else {
+    unregisterFromGcm();
+  }
 }
 
 /**
  * Enables or disables the Google Now background permission.
  * @param {boolean} backgroundEnable true to run in the background.
  *     false to not run in the background.
  */
 function setBackgroundEnable(backgroundEnable) {
   instrumented.permissions.contains({permissions: ['background']},
       function(hasPermission) {
@@ skipping 404 matching lines @@
             lastPollNowPayloads: items.lastPollNowPayloads,
             notificationGroups: items.notificationGroups
           });
 
           pollOptedInWithRecheck();
         }
       });
     });
   }
 });