Fix implementation of CefBrowserView::RequestFocus for Chrome style
browsers. Match Alloy style behavior of requesting browser focus
(calling OnSetFocus) after initial navigation. Add CefView::HasFocus
and CefWindow::GetFocusedView that can be used in combination with
CefWindow::IsActive to determine global keyboard focus.
Update sample applications for the new behavior.
In cefclient:
- Browser receives initial focus via ViewsWindow::RequestBrowserFocus.
- When running with `--show-overlay-browser` (see #3790):
- Give initial focus to the overlay browser.
- Change the overlay popout shortcut to CTRL+SHIFT+O to avoid
assigning focus to the menu in the main window.
- Switching from overlay in the main window to popout browser
window will give focus to the popout browser.
- Switching from popout browser to overlay will leave current focus
unchanged (e.g. in the overlay browser, or somewhere else). User
gesture to activate the main window may be required on Mac/Linux.
- When running with `--no-active` don't give initial focus to either
browser.
In cefsimple:
- Browser receives initial focus via default handling.