Ensure pending callbacks are called only once

src/web_accessible_resources/google-analytics_analytics.js

@@ -85,16 +85,20 @@
                 setTimeout(item.eventCallback, 1);
             };
             if ( Array.isArray(dl) ) {
-                for ( const item of dl ) {
+                dl.push = item => doCallback(item);
+                const q = dl.slice();
+                dl.length = 0;
+                for ( const item of q ) {
                     doCallback(item);
                 }
             }
-            dl.push = item => doCallback(item);
         }
     }
     // empty ga queue
     if ( gaQueue instanceof Function && Array.isArray(gaQueue.q) ) {
-        for ( const entry of gaQueue.q ) {
+        const q = gaQueue.q.slice();
+        gaQueue.q.length = 0;
+        for ( const entry of q ) {
             ga(...entry);
         }
     }