Electron Version: 7.1.1
Operating System: Windows 10 (1803)

If I set the 'margins' option when call webContents.print method,
The app will crash with no error message.

```js
let { remote } = require("electron");
let webContents = remote.getCurrentWebContents();
webContents.print(
  {
    margins: {
      marginType: "custom",
      top: 30,
      bottom: 0,
      left: 0,
      right: 0
    }
  },
  (success, errorType) => {
    if (!success) console.log(errorType);
  }
);
```

shell/browser/api/electron_api_web_contents.cc
Emit("crashed", status == base::TERMINATION_STATUS_PROCESS_WAS_KILLED);
}
void Ws::PluginCrashed(const base::FilePath& plugin_path,
                                base::ProcessId plugin_pid) {
#if BUILDFLAG(ENABLE_PLUGINS)
  content::WebPluginInfo info;
  auto* plugin_service = content::PluginService::GetInstance();
  plugin_service->GetPluginInfoByPath(plugin_path, &info);
  Emit("plugin-crashed", info.name, info.version);
#endif  
}
void Ws::MediaStartedPlaying(const MediaPlayerInfo& video_type,
                                      const content::MediaPlayerId& id) {
  Emit("media-started-playing");
}
void Ws::MediaStoppedPlaying(