### 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 std::string& webrtc_ip_handling_policy) {
  if (GetWebRTCIPHandlingPolicy() == webrtc_ip_handling_policy)
    return;
  ontents()->GetMutableRendererPrefs()->webrtc_ip_handling_policy =
      webrtc_ip_handling_policy;
  ontents()->SyncRendererPrefs();
}
bool WebContents::IsCrashed() const {
  return ontents()->IsCrashed();
}
void WebContents::SetUserAgent(const std::string& user_agent) {
  ontents()->SetUserAgentOverride(
      blink::UserAgentOverride::UserAgentOnly(user_agent), false);
}
std::string WebContents::GetUserAgent() {
  return ontents()->GetUserAgentOverride().ua_string_override;
}
v8::Local<v8::Promise> WebContents::SavePage(
    const base::FilePath& full_file_path,
    const content::SavePageType& save_type) {
  v8::Isolate* isolate = JavascriptEnvironment::GetIsolate();
  gin_helper::Promise<void> promise(isolate);
  v8::Local<v8::Promise> handle = promise.GetHandle();
  auto* handler = new SavePageHandler(ontents(), std::move(promise));
  handler->Handle(full_file_path, save_type);
  return handle;
}
void WebContents::OpenDevTools(gin::Arguments* args) {