### 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 SelectAll();
  void Unselect();
  void Replace(const base::string16& word);
  void ReplaceMisspelling(const base::string16& word);
  uint32_t FindInPage(gin::Arguments* args);
  void StopFindInPage(content::StopFindAction action);
  void ShowDefinitionForSelection();
  void CopyImageAt(int x, int y);
  
  void Focus();
  bool IsFocused() const;
  void TabTraverse(bool reverse);
  
  bool SendIPCMessage(bool internal,
                      bool send_to_all,
                      const std::string& channel,
                      v8::Local<v8::Value> args);
  bool SendIPCMessageWithSender(bool internal,
                                bool send_to_all,
                                const std::string& channel,
                                blink::CloneableMessage args,
                                int32_t sender_id = 0);
  bool SendIPCMessageToFrame(bool internal,
                             bool send_to_all,
                             int32_t frame_id,
                             const std::string& channel,
                             v8::Local<v8::Value> args);
  void PostMessage(const std::string& channel,
                   v8::Local<v8::Value> message,
                   base::Optional<v8::Local<v8::Value>> transfer);