GitLab

Don't slice ui::MouseWheelEvents in tests.

This fixes an ubisan error in ws::EventDispatcher where the creation of a
ui::MouseWheelEvent object was copied into a ui::MouseEvent object, and then
near immediately casted back to a ui::MouseWheelEvent, which it no longer was
because the object was sliced.

Bug: 752271
Change-Id: I9e49369c0ff599b99c1b68ab3785bdd051998568
Reviewed-on: https://chromium-review.googlesource.com/601179Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Elliot Glaysher <erg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491872}