Right now the GLX backend checks for resize on every SwapBuffers
call. If EGL_ANGLE_window_fixed_size is used, it will only resize
when signaled by Chrome.

Bug: chromium:1132827
Change-Id: Ia4ddbbbf6dcf13f46ad564208eccc517de8be33c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2572886Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>