async _startAdb() {
this._isTrackingDevices = true;
await adbProcess.start();
this._trackDevicesCommand.run();
// Device runtimes are detected by running a shell command and checking for
// "firefox-debugger-socket" in the list of currently running processes.
this._timer = setInterval(this.updateRuntimes.bind(this), UPDATE_RUNTIMES_INTERVAL);
}