### 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
ontents()->SelectAll();
}
void WebContents::Unselect() {
  ontents()->CollapseSelection();
}
void WebContents::Replace(const base::string16& word) {
  ontents()->Replace(word);
}
void WebContents::ReplaceMisspelling(const base::string16& word) {
  ontents()->ReplaceMisspelling(word);
}
uint32_t WebContents::FindInPage(gin::Arguments* args) {
  base::string16 search_text;
  if (!args->GetNext(&search_text) || search_text.empty()) {
    gin_helper::ErrorThrower(args->isolate())
        .ThrowError("Must provide a non-empty search content");
    return 0;
  }
  uint32_t request_id = GetNextRequestId();
  gin_helper::Dictionary dict;
  auto options = blink::mojom::FindOptions::New();
  if (args->GetNext(&dict)) {
    dict.Get("forward", &options->forward);
    dict.Get("matchCase", &options->match_case);
    dict.Get("findNext", &options->new_session);
  }
  ontents()->Find(request_id, search_text, std::move(options));
  return request_id;
}
void WebContents::StopFindInPage(content::StopFindAction action) {