--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1623,32 +1623,17 @@ var gBrowserInit = {
     Cu.import("resource:///modules/UpdateTopLevelContentWindowIDHelper.jsm", {})
       .trackBrowserWindow(window);
 
     PlacesToolbarHelper.init();
 
     ctrlTab.readPref();
     gPrefService.addObserver(ctrlTab.prefName, ctrlTab);
 
-    // Initialize the download manager some time after the app starts so that
-    // auto-resume downloads begin (such as after crashing or quitting with
-    // active downloads) and speeds up the first-load of the download manager UI.
-    // If the user manually opens the download manager before the timeout, the
-    // downloads will start right away, and initializing again won't hurt.
-    setTimeout(function() {
-      try {
-        DownloadsCommon.initializeAllDataLinks();
-        Cu.import("resource:///modules/DownloadsTaskbar.jsm", {})
-          .DownloadsTaskbar.registerIndicator(window);
-      } catch (ex) {
-        Cu.reportError(ex);
-      }
-    }, 10000);
-
-    // The object handling the downloads indicator is also initialized here in the
+    // The object handling the downloads indicator is initialized here in the
     // delayed startup function, but the actual indicator element is not loaded
     // unless there are downloads to be displayed.
     DownloadsButton.initializeIndicator();
 
     if (AppConstants.platform != "macosx") {
       updateEditUIVisibility();
       let placesContext = document.getElementById("placesContext");
       placesContext.addEventListener("popupshowing", updateEditUIVisibility);
@@ -1769,16 +1754,31 @@ var gBrowserInit = {
 
       // setup history swipe animation
       gHistorySwipeAnimation.init();
     });
 
     scheduleIdleTask(() => {
       gBrowserThumbnails.init();
     });
+
+    scheduleIdleTask(() => {
+      // Initialize the download manager some time after the app starts so that
+      // auto-resume downloads begin (such as after crashing or quitting with
+      // active downloads) and speeds up the first-load of the download manager UI.
+      // If the user manually opens the download manager before the timeout, the
+      // downloads will start right away, and initializing again won't hurt.
+      try {
+        DownloadsCommon.initializeAllDataLinks();
+        Cu.import("resource:///modules/DownloadsTaskbar.jsm", {})
+          .DownloadsTaskbar.registerIndicator(window);
+      } catch (ex) {
+        Cu.reportError(ex);
+      }
+    }, {timeout: 10000});
   },
 
   // Returns the URI(s) to load at startup.
   _getUriToLoad() {
     // window.arguments[0]: URI to load (string), or an nsIArray of
     //                      nsISupportsStrings to load, or a xul:tab of
     //                      a tabbrowser, which will be replaced by this
     //                      window (for this case, all other arguments are