* 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
}
bool NativeImage::IsTemplateImage() {
  return false;
}
#endif
/
mate::Handle<NativeImage> NativeImage::CreateEmpty(v8::Isolate* isolate) {
  return mate::CreateHandle(isolate, new NativeImage(isolate, gfx::Image()));
}
/
mate::Handle<NativeImage> NativeImage::Create(
    v8::Isolate* isolate, const gfx::Image& image) {
  return mate::CreateHandle(isolate, new NativeImage(isolate, image));
}
/
mate::Handle<NativeImage> NativeImage::CreateFromPNG(
    v8::Isolate* isolate, const char* buffer, size_t length) {
  gfx::Image image = gfx::Image::CreateFrom1xPNGBytes(
      reinterpret_cast<const unsigned char*>(buffer), length);
  return Create(isolate, image);
}
/
mate::Handle<NativeImage> NativeImage::CreateFromJPEG(