This was fixed by https://chromium-review.googlesource.com/1090215 :

commit 022934873f6e8e16f07e36fabe2bebc1635e91c3
Author: Klaus Weidner <klausw@chromium.org>
Date:   Thu Jun 7 02:36:38 2018 +0000

    Fix hit test position after rotations
    
    The pointer matrix for inverse perspective projection wasn't
    getting updated because UpdateProjectionMatrixFromRawValues
    wasn't setting inv_projection_dirty_, so it continued using
    the stale inverse after screen rotations.
    
    Change-Id: Iba2d404e2fdc0c7bdbd824c81b600c76626b35bc
    Reviewed-on: https://chromium-review.googlesource.com/1090215
    Reviewed-by: Bill Orr <billorr@chromium.org>
    Commit-Queue: Klaus Weidner <klausw@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#565153}