* Electron Version: 2.0.0
* Operating System (Platform and Version): Fedora 25
* Last known working Electron version:
Didn't tested all previous versions, however the bug is already present in 1.7.8

**Expected Behavior**
I'm currently trying to figure out if a `MenuItem` was triggered through the accelerator. This is possible to achieve through the information available in the `event` object of the `click` callback.

The structure seems to be the following but isn't currently [documented](https://electronjs.org/docs/api/menu-item).

```js
{
  shiftKey: boolean;
  ctrlKey: boolean;
  altKey: boolean;
  metaKey: boolean;
}
```

When a menu item is triggered through the accelerator, the corresponding flags should normally be set to `true`.

**Actual behavior**
This seems to work fine on MacOS. However, on both Windows (10) and Linux (Fedora 25) all this flags are always `false`.

**To Reproduce**
I quickly setup a [repository](https://github.com/njakob/electron-menuitem-bug) to test the current behavior and how to reproduce it.

```sh
$ git clone https://github.com/njakob/electron-menuitem-bug
$ npm install
$ npm start
```
On Fedora 25:
```js
{ shiftKey: false, ctrlKey: false, altKey: false, metaKey: false }
```
While on MacOS:
```js
{ shiftKey: false, ctrlKey: true, altKey: false, metaKey: false }
```
atom/browser/ui/accelerator_util.cc
atom::AtomMenuModel* model) {
  int count = model->GetItemCount();
  for (int i = 0; i < count; ++i) {
    atom::AtomMenuModel::ItemType type = model->GetTypeAt(i);
    if (type == atom::AtomMenuModel::TYPE_SUBMENU) {
      auto* submodel = model->GetSubmenuModelAt(i);
      GenerateAcceleratorTable(table, submodel);
    } else {
      ui::Accelerator accelerator;
      if (model->GetAcceleratorAtWithParams(i, true, &accelerator)) {
        MenuItem item = {i, model};
        (*table)[accelerator] = item;
      }
    }
  }
}
bool TriggerAcceleratorTableCommand(AcceleratorTable* table,
                                    const ui::Accelerator& accelerator) {
  if (base::ContainsKey(*table, accelerator)) {
    const accelerator_util::MenuItem& item = (*table)[accelerator];
    if (item.model->IsEnabledAt(item.position)) {
      item.model->ActivatedAt(item.position);
      return true;
    }
  }
  return false;
}
}