* **Electron Version** (output of `node_modules/.bin/electron --version`):
  * v4.0.5
* **Operating System** (Platform and Version):
  *  Windows 10 

### Expected Behavior
using  webContents api to print an html file oriention  set to landscape in default printer settings and page size set to A5, 

mainWindow.webContents.print({ silent: true, printBackground: false, deviceName: 'HP LaserJet 1020' })

My issue is : it is not printing as defined in the default printer settings

but it currently printing is deviceName not set

and need to send mainWindow.webContents.print() api to silently and printer name 

### To Reproduce
If you provide a URL, please list the commands required to clone/setup/run your repo e.g.
```sh
$ git clone git@github.com:shabeer-mdy/electron-quick-start.git
$ npm install
$ npm start || electron .
```
and set any printer name to  mainWindow.webContents.print({ silent: true, printBackground: false, deviceName: 'HP LaserJet 1020' })

set any installed printer name 



shell/browser/api/atom_api_web_contents.cc
const blink::WebDeviceEmulationParams& params) {
  if (type_ == Type::REMOTE)
    return;
  auto* frame_host = web_contents()->GetMainFrame();
  if (frame_host) {
    auto* widget_host =
        frame_host ? frame_host->GetView()->GetRenderWidgetHost() : nullptr;
    if (!widget_host)
      return;
    widget_host->Send(new WidgetMsg_EnableDeviceEmulation(
        widget_host->GetRoutingID(), params));
  }
}
void WebContents::DisableDeviceEmulation() {
  if (type_ == Type::REMOTE)
    return;
  auto* frame_host = web_contents()->GetMainFrame();
  if (frame_host) {
    auto* widget_host =
        frame_host ? frame_host->GetView()->GetRenderWidgetHost() : nullptr;
    if (!widget_host)
      return;
    widget_host->Send(
        new WidgetMsg_DisableDeviceEmulation(widget_host->GetRoutingID()));
  }
}
void WebContents::ToggleDevTools() {