### 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 SendInputEvent(v8::Isolate* isolate, v8::Local<v8::Value> input_event);
  
  void BeginFrameSubscription(gin::Arguments* args);
  void EndFrameSubscription();
  
  void StartDrag(const gin_helper::Dictionary& item, gin::Arguments* args);
  
  
  v8::Local<v8::Promise> CapturePage(gin::Arguments* args);
  
  bool IsGuest() const;
  void AttachToIframe(content::WebContents* embedder_web_contents,
                      int embedder_frame_id);
  void DetachFromOuterFrame();
  
  bool IsOffScreen() const;
#if BUILDFLAG(ENABLE_OSR)
  void OnPaint(const gfx::Rect& dirty_rect, const SkBitmap& bitmap);
  void StartPainting();
  void StopPainting();
  bool IsPainting() const;
  void SetFrameRate(int frame_rate);
  int GetFrameRate() const;
#endif
  void Invalidate();
  gfx::Size GetSizeForNewRenderView(content::WebContents*) override;
  
  void SetZoomLevel(double level);
  double GetZoomLevel() const;