How to use performance.memory API in web worker

I am trying to get heap usage of objects for webworker.

The performance.memory api is providing result like

MemoryInfo {
  jsHeapSizeLimit: 793000000,
  usedJSHeapSize: 10000000,
  totalJSHeapSize: 31200000
}

But inside web worker when I try to console.log the memory api is undefined. How can i get memory usage of webworker? Is the performance.memory in main thread(dont know what to call) supposed to retrieve all usages including web worker. I am totally confused

Update Code

<<<main.js>>>
worker = new Worker("worker.js")

<<<worker.js>>>
var perfObj = self.performance;
self.onmessage = function(e) {
  initialize();
}

function initialize() {

  _sockHandler= new SockerHandler(socketURL);
}
class SockerHandler{

 constructor(url) {
   var ws = new WebSocket(url);
   ws.onmessage = (event) => {
     console.log("memory = ", perfObj.memory)
     }
   }
}