* **Electron Version** 4.0.4
* **Operating System** Windows 10 32 bit
* **Last known working Electron version** 3.1.3

### Expected Behavior
`webContents.print()` shold send print job to a printer

### Actual behavior
Nothing happens. Callback doesn't gets called. 

`printToPDF` works though.

### To Reproduce
```
let deviceName = 'HP LaserJet 1020'
let options = {deviceName, silent: true}
win.webContents.print({}, (err) => {
    if (!err)
      console.error('printing failed')
})
```

atom/browser/api/atom_api_web_contents.cc
const_cast<SkBitmap&>(bitmap).setAlphaType(kPremul_SkAlphaType);
  promise.Resolve(gfx::Image::CreateFrom1xBitmap(bitmap));
}
}  
struct WebContents::FrameDispatchHelper {
  WebContents* api_web_contents;
  content::RenderFrameHost* rfh;
  bool Send(IPC::Message* msg) { return rfh->Send(msg); }