We are assuming that there will always be only one target for a web page. In the GTK port (and WinCairo once they enable coordinated graphics) we destroy the render target when leaving AC mode, and a new one is created when re-entering AC mode. Since the file descriptor is released on the first target and adopted by libwpe, the second target passes -1 as host fd to libwpe, and the new surface created by the target is not properly registered in the wayland compositor. That means that frame requests for the new target are simply ignored by the wayland compositor, it returns early on surfacxe frame when the surface doesn't have a view backend client.
Created attachment 370937 [details]
Comment on attachment 370937 [details]
Attachment 370937 [details] did not pass win-ews (win):
New failing tests:
Created attachment 370940 [details]
Archive of layout-test-results from ews215 for win-future
The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews215 Port: win-future Platform: CYGWIN_NT-10.0-17763-3.0.5-338.x86_64-x86_64-64bit
Committed r245956: <https://trac.webkit.org/changeset/245956>