- Windows: SDK version 10.0.20348.0 is now required.
- MacOS: SDK version 12.3 (Xcode 13.3) is now required.
- Legacy swiftshader binaries (`swiftshader/*` on Win/Linux and
`libswiftshader_*.dylib` on MacOS) have been removed (see issue #3176).
We need to override ChromeMimeHandlerViewGuestDelegate to handle
OnGuestAttached/Detached callbacks in order to account for the guest renderer
process hosting the PDF extension.
Additional work will be required to account for the renderer process hosting the
PDF viewer when using `--enable-features=PdfUnseasoned` (see issue #2969).