### 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.h
void MessageSync(bool internal,
                   const std::string& channel,
                   blink::CloneableMessage arguments,
                   MessageSyncCallback callback) override;
  void MessageTo(bool internal,
                 bool send_to_all,
                 int32_t web_contents_id,
                 const std::string& channel,
                 blink::CloneableMessage arguments) override;
  void MessageHost(const std::string& channel,
                   blink::CloneableMessage arguments) override;
  void UpdateDraggableRegions(
      std::vector<mojom::DraggableRegionPtr> regions) override;
  void SetTemporaryZoomLevel(double level) override;
  void DoGetZoomLevel(DoGetZoomLevelCallback callback) override;
  
  
  void OnGetZoomLevel(content::RenderFrameHost* frame_host,
                      IPC::Message* reply_msg);
  void InitZoomController(content::WebContents* web_contents,
                          const gin_helper::Dictionary& options);
  v8::Global<v8::Value> session_;
  v8::Global<v8::Value> devtools_web_contents_;
  v8::Global<v8::Value> debugger_;
  std::unique_ptr<ElectronJavaScriptDialogManager> dialog_manager_;
  std::unique_ptr<WebViewGuestDelegate> guest_delegate_;
  std::unique_ptr<FrameSubscriber> frame_subscriber_;
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
  std::unique_ptr<extensions::ScriptExecutor> script_executor_;
#endif