function setup (parentWindow) {
  var view = views[parentWindow.id] = new BrowserView({
    webPreferences: {
      defaultEncoding: 'utf-8'
    }
  })
  view.webContents.loadFile(path.join(__dirname, 'fg', 'tab-switcher', 'index.html'))
  wcTrust.setWcTrust(view.webContents, wcTrust.TRUST.TRUSTED)
}
Tab Switchers

NOTES
- There is one tab-switcher per BrowserWindow instance
- Switcher views are created with each browser window and then shown/hidden as needed