diff -r 000000000000 -r 6474c204b198 toolkit/components/places/PlacesCategoriesStarter.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/places/PlacesCategoriesStarter.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,112 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 sts=2 expandtab
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+////////////////////////////////////////////////////////////////////////////////
+//// Constants
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+// Fired by TelemetryPing when async telemetry data should be collected.
+const TOPIC_GATHER_TELEMETRY = "gather-telemetry";
+
+// Seconds between maintenance runs.
+const MAINTENANCE_INTERVAL_SECONDS = 7 * 86400;
+
+////////////////////////////////////////////////////////////////////////////////
+//// Imports
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+Components.utils.import("resource://gre/modules/PlacesUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PlacesDBUtils",
+                                  "resource://gre/modules/PlacesDBUtils.jsm");
+
+/**
+ * This component can be used as a starter for modules that have to run when
+ * certain categories are invoked.
+ */
+function PlacesCategoriesStarter()
+{
+  Services.obs.addObserver(this, TOPIC_GATHER_TELEMETRY, false);
+  Services.obs.addObserver(this, PlacesUtils.TOPIC_SHUTDOWN, false);
+
+  // nsINavBookmarkObserver implementation.
+  let notify = (function () {
+    if (!this._notifiedBookmarksSvcReady) {
+      // For perf reasons unregister from the category, since no further
+      // notifications are needed.
+      Cc["@mozilla.org/categorymanager;1"]
+        .getService(Ci.nsICategoryManager)
+        .deleteCategoryEntry("bookmarks-observer", this, false);
+      // Directly notify PlacesUtils, to ensure it catches the notification.
+      PlacesUtils.observe(null, "bookmarks-service-ready", null);
+    }
+  }).bind(this);
+  [ "onItemAdded", "onItemRemoved", "onItemChanged", "onBeginUpdateBatch",
+    "onEndUpdateBatch", "onItemVisited",
+    "onItemMoved" ].forEach(function(aMethod) {
+      this[aMethod] = notify;
+    }, this);
+}
+
+PlacesCategoriesStarter.prototype = {
+  //////////////////////////////////////////////////////////////////////////////
+  //// nsIObserver
+
+  observe: function PCS_observe(aSubject, aTopic, aData)
+  {
+    switch (aTopic) {
+      case PlacesUtils.TOPIC_SHUTDOWN:
+        Services.obs.removeObserver(this, PlacesUtils.TOPIC_SHUTDOWN);
+        Services.obs.removeObserver(this, TOPIC_GATHER_TELEMETRY);
+        let globalObj =
+          Cu.getGlobalForObject(PlacesCategoriesStarter.prototype);
+        let descriptor =
+          Object.getOwnPropertyDescriptor(globalObj, "PlacesDBUtils");
+        if (descriptor.value !== undefined) {
+          PlacesDBUtils.shutdown();
+        }
+        break;
+      case TOPIC_GATHER_TELEMETRY:
+        PlacesDBUtils.telemetry();
+        break;
+      case "idle-daily":
+        // Once a week run places.sqlite maintenance tasks.
+        let lastMaintenance = 0;
+        try {
+          lastMaintenance =
+            Services.prefs.getIntPref("places.database.lastMaintenance");
+        } catch (ex) {}
+        let nowSeconds = parseInt(Date.now() / 1000);
+        if (lastMaintenance < nowSeconds - MAINTENANCE_INTERVAL_SECONDS) {
+          PlacesDBUtils.maintenanceOnIdle();
+        }
+        break;
+      default:
+        throw new Error("Trying to handle an unknown category.");
+    }
+  },
+
+  //////////////////////////////////////////////////////////////////////////////
+  //// nsISupports
+
+  classID: Components.ID("803938d5-e26d-4453-bf46-ad4b26e41114"),
+
+  _xpcom_factory: XPCOMUtils.generateSingletonFactory(PlacesCategoriesStarter),
+
+  QueryInterface: XPCOMUtils.generateQI([
+    Ci.nsIObserver
+  , Ci.nsINavBookmarkObserver
+  ])
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Module Registration
+
+let components = [PlacesCategoriesStarter];
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);