perf_hooks: ignore duplicated entries in observer

PerformanceObserver should add to observing only unique entry types.

PR-URL: #29442
Reviewed-By: David Carlier <[email protected]>
Reviewed-By: Minwoo Jung <[email protected]>

Author: fanatid

lib/perf_hooks.js

@@ -354,6 +354,7 @@ class PerformanceObserver extends AsyncResource {
     for (var n = 0; n < entryTypes.length; n++) {
       const entryType = entryTypes[n];
       const list = getObserversList(entryType);
+      if (this[kTypes][entryType]) continue;
       const item = { obs: this };
       this[kTypes][entryType] = item;
       L.append(list, item);

test/parallel/test-performanceobserver.js

@@ -62,6 +62,12 @@ assert.strictEqual(counts[NODE_PERFORMANCE_ENTRY_TYPE_FUNCTION], 0);
                                    'for option "entryTypes"'
                         });
   });
+
+  const obs = new PerformanceObserver(common.mustNotCall());
+  obs.observe({ entryTypes: ['mark', 'mark'] });
+  obs.disconnect();
+  performance.mark('42');
+  assert.strictEqual(counts[NODE_PERFORMANCE_ENTRY_TYPE_MARK], 0);
 }
 
 // Test Non-Buffered