It doesn't really make sense to try to create the X11 capturer if we are
running under Wayland; nor does it make sense to create the PipeWire
capturer if we are going to fail to actually start a stream with it.
This change addresses both of these issues by exposing an IsSupported
method on BaseCapturerPipeWire and checking that we are not running
under Wayland before creating the X11 capturer.
Bug: chromium:1374436
Change-Id: Ieb291307376010e084824124ea8fde065545337c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/279163
Auto-Submit: Alexander Cooper <alcooper@chromium.org>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>
Commit-Queue: Alexander Cooper <alcooper@chromium.org>
Cr-Commit-Position: refs/heads/main@{#38474}
