src/vs/base/browser/broadcast.ts/BroadcastDataChannel/postData
class BroadcastDataChannel:	postData(data: T): void {
		if (this.broadcastChannel) {
			this.broadcastChannel.postMessage(data);
		} else {
			// remove previous changes so that event is triggered even if new changes are same as old changes
			window.localStorage.removeItem(this.channelName);
			window.localStorage.setItem(this.channelName, JSON.stringify(data));
		}
	}