### 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
std::string accept_languages =
      g_browser_process->GetApplicationLocale() + ",";
  for (auto const& language : electron::GetPreferredLanguages()) {
    if (language == g_browser_process->GetApplicationLocale())
      continue;
    accept_languages += language + ",";
  }
  accept_languages.pop_back();
  prefs->accept_languages = accept_languages;
#if defined(OS_LINUX) || defined(OS_WIN)
  
  static const base::NoDestructor<gfx::FontRenderParams> params(
      gfx::GetFontRenderParams(gfx::FontRenderParamsQuery(), nullptr));
  prefs->should_antialias_text = params->antialiasing;
  prefs->use_subpixel_positioning = params->subpixel_positioning;
  prefs->hinting = params->hinting;
  prefs->use_autohinter = params->autohinter;
  prefs->use_bitmaps = params->use_bitmaps;
  prefs->subpixel_rendering = params->subpixel_rendering;
#endif
  
  if (auto interval = GetCursorBlinkInterval())
    prefs->caret_blink_interval = *interval;
  
  new WebContentsPreferences(ontents(), options);
  
  ontents()->NotifyPreferencesChanged();
  WebContentsPermissionHelper::CreateForWebContents(ontents());
  SecurityStateTabHelper::CreateForWebContents(ontents());