Bug 1573431 - Fix the issue that the "number of trackers" won't show if reopening it without a mouse move. r=nhnt11

We show the number of tracker if the data is up-to-date when opening the
panel.

Differential Revision: https://phabricator.services.mozilla.com/D41747

--HG--
extra : moz-landing-system : lando

browser/base/content/browser-siteProtections.js

@@ -1877,6 +1877,12 @@ var gProtectionsHandler = {
       );
     }
 
+    // Show the blocked tracker counter if it is not updating. We can sure the
+    // data in the tracker counter is up-to-date here, so we can show it.
+    if (!this._updatingFooter) {
+      this._protectionsPopupTrackersCounterBox.toggleAttribute("showing", true);
+    }
+
     // Update the tooltip of the blocked tracker counter.
     this.maybeUpdateEarliestRecordedDateTooltip();
   },