* Electron version: latest
* Operating system: MacOS

The TouchBar API (and MacOS in general) let's you pass an `imageNamed` param to NSImage to get the default OS image. For example: `[NSImage imageNamed:@"NSTouchBarGoUpTemplate"];` creates an NSImage with the default up chevron icon on MacOS. 

It would be pretty neat-o to allow TouchBar users to do something like this: 

```javascript
new TouchBarButton({
  icon: nativeImage.createFromMacOSNamedImage('NSTouchBarGoUpTemplate')
})
```

...and maybe that would just no-op with `nativeImage.createEmpty()` on non-MacOS platforms. 

I guess this is really bigger than just TouchBar because this API could benefit `Menu` for example as well, or anywhere else where you use `nativeImage`. 


atom/common/api/atom_api_native_image.cc
std::string filename(path.BaseName().RemoveExtension().AsUTF8Unsafe());
  
  
  for (const auto& kScaleFactorPair : kScaleFactorPairs) {
    if (base::EndsWith(filename, kScaleFactorPair.name,
                       base::CompareCase::INSENSITIVE_ASCII))
      return kScaleFactorPair.scale;
  }
  return 1.0f;
}
float GetScaleFactorFromOptions(mate::Arguments* args) {
  float scale_factor = 1.0f;
  mate::Dictionary options;
  if (args->GetNext(&options))
    options.Get("scaleFactor", &scale_factor);
  return scale_factor;
}
bool AddImageSkiaRep(gfx::ImageSkia* image,