Portals: Add test for touch transfer across portal reactivation

Bug: 914376
Change-Id: I1c14e678e3b34989492992cdd273ce3b0feba14a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1674494
Reviewed-by: David Trainor <dtrainor@chromium.org>
Reviewed-by: Kevin McNee <mcnee@chromium.org>
Commit-Queue: Adithya Srinivasan <adithyas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#679744}
3 files changed