Cleaning data associated with the card upon deletion.

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 5a6e6aeae5f7a0b3a7e2a93106ade2ba06f81ee8..e6e32192bf36a102fe0bbf308888aaf1aa7938db 100644
--- a/chrome/browser/resources/google_now/background.js
+++ b/chrome/browser/resources/google_now/background.js
@@ -299,7 +299,7 @@ function showNotificationCards(cards) {
             if (!(chromeNotificationId in cards)) {
               console.log(
                   'showNotificationCards-delete ' + chromeNotificationId);
-              cardSet.clear(chromeNotificationId);
+              cardSet.clear(chromeNotificationId, false);
             }
           }
 
@@ -815,15 +815,16 @@ function onNotificationClosed(chromeNotificationId, byUser) {
   tasks.add(DISMISS_CARD_TASK_NAME, function() {
     dismissalAttempts.start();
 
-    // Deleting the notification in case it was re-added while this task was
-    // scheduled, waiting for execution.
-    cardSet.clear(chromeNotificationId);
-
     instrumented.storage.local.get(
         ['pendingDismissals', 'notificationsData'], function(items) {
       items.pendingDismissals = items.pendingDismissals || [];
       items.notificationsData = items.notificationsData || {};
 
+      // Deleting the notification in case it was re-added while this task was
+      // scheduled, waiting for execution; also cleaning notification's data
+      // from storage.
+      cardSet.clear(chromeNotificationId, true);
+
       var notificationData = items.notificationsData[chromeNotificationId];
 
       if (notificationData && notificationData.dismissals) {