### 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
return ontents()->GetMainFrame()->GetProcess()->GetID();
}
base::ProcessId WebContents::GetOSProcessID() const {
  base::ProcessHandle process_handle =
      ontents()->GetMainFrame()->GetProcess()->GetProcess().Handle();
  return base::GetProcId(process_handle);
}
base::ProcessId WebContents::GetOSProcessIdForFrame(
    const std::string& name,
    const std::string& document_url) const {
  for (auto* frame : ontents()->GetAllFrames()) {
    if (frame->GetFrameName() == name &&
        frame->GetLastCommittedURL().spec() == document_url) {
      return base::GetProcId(frame->GetProcess()->GetProcess().Handle());
    }
  }
  return base::kNullProcessId;
}
WebContents::Type WebContents::GetType() const {
  return type_;
}
bool WebContents::Equal(const WebContents* ontents) const {