Enable constructing Page{Reveal|Swap}Event
As per spec
https://html.spec.whatwg.org/multipage/nav-history-apis.html#the-pagerevealevent-interface
https://html.spec.whatwg.org/multipage/nav-history-apis.html#pageswapevent
Bug: 354588516
Change-Id: I108e5a16af2fc4da3d5030589c820c9fd309bf65
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5724461
Reviewed-by: Khushal Sagar khushalsagar@chromium.org
Commit-Queue: Noam Rosenthal nrosenthal@chromium.org
Cr-Commit-Position: refs/heads/main@{#1331321}