Use out-of-process iframe PDF Viewer

Determines whether the PDF viewer in Microsoft Edge uses an out-of-process iframe (OOPIF).
This is the new PDF viewer architecture going forward, as it's simpler in design and makes adding new features easier. The current GuestView PDF viewer, which relies on an outdated and overly complex architecture, is being deprecated.

If you enable this policy or don't configure it, Microsoft Edge uses the OOPIF PDF viewer architecture. The default behavior will be decided by Microsoft Edge.

If you disable this policy, Microsoft Edge strictly uses the existing GuestView PDF viewer. This approach embeds a web page with its own separate frame tree into another web page.

This policy will be removed in the future, after the OOPIF PDF viewer feature has fully rolled out.