Implement the ability to get all notifications in Chromium.

content/child/notifications/notification_manager.cc

Index: content/child/notifications/notification_manager.cc
diff --git a/content/child/notifications/notification_manager.cc b/content/child/notifications/notification_manager.cc
index 29a32323fc8f5d78ef57fd9251422443123d17e5..b17611d0e35929e2da73c5e6e88fda5de127eeeb 100644
--- a/content/child/notifications/notification_manager.cc
+++ b/content/child/notifications/notification_manager.cc
@@ -280,8 +280,11 @@ void NotificationManager::OnDidGetNotifications(
 
   for (size_t i = 0; i < notification_infos.size(); ++i) {
     blink::WebPersistentNotificationInfo web_notification_info;
+
+    // TODO(peter): Stop converting the notification id to a string when the
+    // Blink API has been updated to support integral ids.
     web_notification_info.persistentNotificationId =
-        blink::WebString::fromUTF8(notification_infos[i].first);
+        base::Int64ToString16(notification_infos[i].first);
     web_notification_info.data =
         ToWebNotificationData(notification_infos[i].second);