### 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
static base::NoDestructor<base::IDMap<WebContents*>> s_all_ontents;
  return *s_all_ontents;
}
void OnCapturePageDone(gin_helper::Promise<gfx::Image> promise,
                       const SkBitmap& bitmap) {
  
  promise.Resolve(gfx::Image::CreateFrom1xBitmap(bitmap));
}
base::Optional<base::TimeDelta> GetCursorBlinkInterval() {
#if defined(OS_MAC)
  base::TimeDelta interval;
  if (ui::TextInsertionCaretBlinkPeriod(&interval))
    return interval;
#elif defined(OS_LINUX)
  if (auto* linux_ui = views::LinuxUI::instance())
    return linux_ui->GetCursorBlinkInterval();
#elif defined(OS_WIN)
  const auto system_msec = ::GetCaretBlinkTime();
  if (system_msec != 0) {
    return (system_msec == INFINITE)
               ? base::TimeDelta()
               : base::TimeDelta::FromMilliseconds(system_msec);
  }
#endif
  return base::nullopt;
}
#if BUILDFLAG(ENABLE_PRINTING)
bool IsDeviceNameValid(const base::string16& device_name) {