Track menu popup visibility and propagate zoom level to the popup. Add menu_popup_visible_ flag, SendMenuPopupZoom(), and call it when creating/showing the popup and when adjusting zoom. Make CreateNewTab accept an optional URL and route popup/new-tab flows to it. Prevent per-tab child closes from triggering app shutdown by tracking closing_tab_browsers_ and adding ForgetClosingTabBrowser(). Treat MenuPopup role specially when enabling frame hit-testing.
Platform: remove usage of ApplyRoundedBrowserRegion and switch menu popup sizing to use resized client_size helpers (consolidate calculations across Win/Mac/Linux). UI: update menu-popup CSS/JS (new styling, font, zoom formatting API via NebulaMenuPopup.setZoomLevel), wire settings to use nebulaNative.postMessage for new-tab, and remove the static menu-popup.html. Misc: small chrome CSS/JS tweaks and ensure chrome state includes zoomLevel.
Andrew Zambazos
c514e4faec