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

chrome/browser/resources/google_now/background.js

Index: chrome/browser/resources/google_now/background.js
diff --git a/chrome/browser/resources/google_now/background.js b/chrome/browser/resources/google_now/background.js
index e24f70b499b482ea73d0a51204315cb4d34bcb2f..9da2b04dfabc7b9f9748f1be0c405d96e575d482 100644
--- a/chrome/browser/resources/google_now/background.js
+++ b/chrome/browser/resources/google_now/background.js
@@ -202,6 +202,7 @@ 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);
@@ -1027,7 +1028,8 @@ function stopPollingCards() {
  */
 function initialize() {
   recordEvent(GoogleNowEvent.EXTENSION_START);
-  registerForGcm();
+  // TODO(skare): Reenable, after signin.
+  unregisterFromGcm();
   onStateChange();
 }
 
@@ -1311,6 +1313,21 @@ function getGcmRegistrationId() {
 }
 
 /**
+ * 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.