Resize popover on Safari only when the size of its content doesn't change anymore

safari/ext/popup.js

 (function()
 {
   // Safari doesn't adjust the size of the popover automatically to the size
   // of its content, like when the ad counter is expanded/collapsed. So we add
   // event listeners to do so.
   var mayResize = true;
+  var resizingScheduled = false;
 
   var updateSize = function()
   {
-    if (mayResize)
+    if (mayResize && !resizingScheduled)
     {
-      safari.self.width = document.body.offsetWidth;
-      safari.self.height = document.body.offsetHeight;
+      setTimeout(function()
+      {
+        safari.self.width = document.body.offsetWidth;
+        safari.self.height = document.body.offsetHeight;
+
+        resizingScheduled = false;
+      }, 0);
+
+      resizingScheduled = true;
     }
   };
 
   window.addEventListener("load", function()
   {
     updateSize();
 
     var MutationObserver = window.MutationObserver || window.WebKitMutationObserver;
     if (MutationObserver)
     {
@@ skipping 35 matching lines @@
 
   window.ext = {
     __proto__: backgroundPage.ext,
     closePopup: function()
     {
       safari.self.hide();
     }
   };
   window.TabMap = backgroundPage.TabMap;
 })();