Now component extension (v1): unregister from GCM on startup

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 184 matching lines @@
   }
 
   return false;
 }
 
 var tasks = buildTaskManager(areTasksConflicting);
 
 // Add error processing to API calls.
 wrapper.instrumentChromeApiFunction('gcm.onMessage.addListener', 0);
 wrapper.instrumentChromeApiFunction('gcm.register', 1);
+wrapper.instrumentChromeApiFunction('gcm.unregister', 0);
 wrapper.instrumentChromeApiFunction('metricsPrivate.getVariationParams', 1);
 wrapper.instrumentChromeApiFunction('notifications.clear', 1);
 wrapper.instrumentChromeApiFunction('notifications.create', 2);
 wrapper.instrumentChromeApiFunction('notifications.getPermissionLevel', 0);
 wrapper.instrumentChromeApiFunction('notifications.update', 2);
 wrapper.instrumentChromeApiFunction('notifications.getAll', 0);
 wrapper.instrumentChromeApiFunction(
     'notifications.onButtonClicked.addListener', 0);
 wrapper.instrumentChromeApiFunction('notifications.onClicked.addListener', 0);
 wrapper.instrumentChromeApiFunction('notifications.onClosed.addListener', 0);
@@ skipping 805 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);
-  registerForGcm();
+  // 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) {
@@ skipping 263 matching lines @@
               resolve(registrationId);
             } else {
               reject();
             }
           });
         });
       });
 }
 
 /**
+ * Unregisters from GCM if previously registered.
+ */
+function unregisterFromGcm() {
+  fillFromChromeLocalStorage({gcmRegistrationId: undefined})
+      .then(function(items) {
+        if (items.gcmRegistrationId) {
+          console.log('Unregistering from gcm.');
+          chrome.storage.local.remove(
+              ['gcmNotificationKey', 'gcmRegistrationId']);
+          instrumented.gcm.unregister(function() {});

[fgorski, 2015/04/23 22:38:37]

Would it make sense to call chrome.storage.local.remove() after successful
unregistration? that way you make sure you really unregister.

If the unregistration fails (perhaps there is no network), you will still be
making GCM connections, with no way of knowing that you are registered.

[skare_, 2015/04/23 22:50:53]

uploaded new snapshot -- via if(!chrome.runtime.lastError){clearStorage()} in
the gcm.unregister callback?

+        }
+      });
+}
+
+/**
  * Polls the optin state.
  * Sometimes we get the response to the opted in result too soon during
  * push messaging. We'll recheck the optin state a few times before giving up.
  */
 function pollOptedInWithRecheck() {
   /**
    * Cleans up any state used to recheck the opt-in poll.
    */
   function clearPollingState() {
     localStorage.removeItem('optedInCheckCount');
@@ skipping 146 matching lines @@
             lastPollNowPayloads: items.lastPollNowPayloads,
             notificationGroups: items.notificationGroups
           });
 
           pollOptedInWithRecheck();
         }
       });
     });
   }
 });