Add extra wait time between Crux calls (#3536)

lib/plugins/crux/index.js

@@ -23,6 +23,12 @@ const DEFAULT_METRICS_SUMMARY = [
   'originLoadingExperience.*.CUMULATIVE_LAYOUT_SHIFT_SCORE.*'
 ];
 
+function wait(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+const CRUX_WAIT_TIME = 300;
+
 module.exports = {
   name() {
     return path.basename(__dirname);
@@ -120,6 +126,7 @@ module.exports = {
                 );
               }
             }
+            await wait(CRUX_WAIT_TIME);
           }
           queue.postMessage(make('crux.summary', originResult, { group }));
         }
@@ -161,6 +168,7 @@ module.exports = {
                 );
               }
             }
+            await wait(CRUX_WAIT_TIME);
           }
           // Attach origin result so we can show it in the HTML
           urlResult.originLoadingExperience =