### Preflight Checklist
* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 10.1.1
* **Operating System:**
  * macOS 10.15.4

We recently started launching as hidden on macOS (that is, `show: false` or `browserWindow.hide()` while loading the page, followed by `browserWindow.show()` when the dock icon is clicked). This results in some busted focus behavior on the first activation of the window. The second activation restores it.

### Expected Behavior
The guest page receives a `focus` event on the first activation of the app, when created with `show: false`.

### Actual Behavior
The guest page doesn't receive the first `focus` event. Subsequent activations do trigger a `focus` event.

### To Reproduce
[Electron Fiddle](https://gist.github.com/CharlieHess/c507468cd40630d04f58c6514100b997)

shell/browser/api/electron_api_web_contents.cc
content::RenderFrameHost* render_frame_host,
    const GURL& security_origin,
    blink::mojom::MediaStreamType type) {
  auto* ontents =
      content::WebContents::FromRenderFrameHost(render_frame_host);
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(ontents);
  return permission_helper->CheckMediaAccessPermission(security_origin, type);
}
void WebContents::RequestMediaAccessPermission(
    content::WebContents* ontents,
    const content::MediaStreamRequest& request,
    content::MediaResponseCallback callback) {
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(ontents);
  permission_helper->RequestMediaAccessPermission(request, std::move(callback));
}
void WebContents::RequestToLockMouse(content::WebContents* ontents,
                                     bool user_gesture,
                                     bool last_unlocked_by_target) {
  auto* permission_helper =
      WebContentsPermissionHelper::FromWebContents(ontents);
  permission_helper->RequestPointerLockPermission(user_gesture);
}
std::unique_ptr<content::BluetoothChooser> WebContents::RunBluetoothChooser(
    content::RenderFrameHost* frame,
    const content::BluetoothChooser::EventHandler& event_handler) {
  return std::make_unique<BluetoothChooser>(this, event_handler);
}
content::JavaScriptDialogManager* WebContents::GetJavaScriptDialogManager(