### 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
const content::LoadCommittedDetails& details) {
  Emit("navigation-entry-committed", details.entry->GetURL(),
       details.is_same_document, details.did_replace_entry);
}
bool WebContents::GetBackgroundThrottling() const {
  return background_throttling_;
}
void WebContents::SetBackgroundThrottling(bool allowed) {
  background_throttling_ = allowed;
  auto* rfh = ontents()->GetMainFrame();
  if (!rfh)
    return;
  auto* rwhv = rfh->GetView();
  if (!rwhv)
    return;
  auto* rwh_impl =
      static_cast<content::RenderWidgetHostImpl*>(rwhv->GetRenderWidgetHost());
  if (!rwh_impl)
    return;
  rwh_impl->disable_hidden_ = !background_throttling_;
  ontents()->GetRenderViewHost()->SetSchedulerThrottling(allowed);
  if (rwh_impl->is_hidden()) {
    rwh_impl->WasShown(base::nullopt);
  }
}
int WebContents::GetProcessID() const {