key events in atom shell

Let's say I want to have a key event only on my compiled application with atom shell.

var app = require('app');
var BrowserWindow = require('browser-window');
require('crash-reporter').start();

app.on('ready', function() {
  win = new BrowserWindow({ fullscreen: true, frame: false });
  win.hide();
  win.loadUrl("http://localhost:3000");

  win.webContents.on('did-finish-load', function() {
    win.show();
    win.focus();
  });

  process.on('uncaughtException', app.quit);
});

How could I bind a keyboard event on the web browser? Eg,

win.on('keypress', 'left-arrow', function() {
  win.webContents.goBack();
});