### 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
#include "content/public/browser/native_web_keyboard_event.h"
#include "content/public/browser/navigation_details.h"
#include "content/public/browser/navigation_entry.h"
#include "content/public/browser/navigation_handle.h"
#include "content/public/browser/plugin_service.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/render_widget_host.h"
#include "content/public/browser/render_widget_host_view.h"
#include "content/public/browser/service_worker_context.h"
#include "content/public/browser/site_instance.h"
#include "content/public/browser/storage_partition.h"
#include "content/public/browser/ontents.h"
#include "content/public/common/referrer_type_converters.h"
#include "electron/buildflags/buildflags.h"
#include "electron/shell/common/api/api.mojom.h"
#include "gin/arguments.h"
#include "gin/data_object_builder.h"
#include "gin/handle.h"
#include "gin/object_template_builder.h"
#include "gin/wrappable.h"
#include "mojo/public/cpp/bindings/associated_remote.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "mojo/public/cpp/system/platform_handle.h"
#include "ppapi/buildflags/buildflags.h"
#include "shell/browser/api/electron_api_browser_window.h"
#include "shell/browser/api/electron_api_debugger.h"
#include "shell/browser/api/electron_api_session.h"