* This is to enable more browser-like behavior so that users who run third-party code
will not be DOS'ed with alerts and confirms. This is already handled like this
in most major browsers so this will greatly help these developers
Chromium already includes the necessary plumbing to manage the
visibility properties and `visibilitychange` event so this gets rid of
most of our custom logic for `BrowserWindow` and `BrowserView`.
Note that `webview` remains unchanged and is still affected by the issues
listed below.
User facing changes:
- The `document` visibility properties and `visibilitychange` event are
now also updated/fired in response to occlusion changes on macOS. In
other words, `document.visibilityState` will now be `hidden` on macOS
if the window is occluded by another window.
- Previously, `visibilitychange` was also fired by *both* Electron and
Chromium in some cases (e.g. when hiding the window). Now it is only
fired by Chromium so you no longer get duplicate events.
- The visiblity state of `BrowserWindow`s created with `{ show: false }`
is now initially `visible` until the window is shown and hidden.
- The visibility state of `BrowserWindow`s with `backgroundThrottling`
disabled is now permanently `visible`.
This should also fix#6860 (but not for `webview`).
