src/vs/workbench/services/extensions/common/rpcProtocol.ts/RPCProtocol/_onDidReceiveAcknowledge
class RPCProtocol:	private _onDidReceiveAcknowledge(req: number): void {
		// The next possible unresponsive time is now + delta.
		this._unresponsiveTime = Date.now() + RPCProtocol.UNRESPONSIVE_TIME;
		this._unacknowledgedCount--;
		if (this._unacknowledgedCount === 0) {
			// No more need to check for unresponsive
			this._asyncCheckUresponsive.cancel();
		}
		// The ext host is responsive!
		this._setResponsiveState(ResponsiveState.Responsive);
	}