ozone: evdev: Move EventModifiersEvdev usage to EventFactoryEvdev
This is part of a series moving IO on evdev devices to a fast thread,
since UI thread is too slow for the cursor.
EventModifiersEvdev is a UI thread object, so move all remaining
ui::Event construction outside of the device-specific objects. Devices
no longer get a EventModifiersEvdev* since they will execute on a
different thread.
This completes the series moving ui::Event construction out of device
objects and into EventFactoryEvdev.
BUG=449710
TEST=boot link_freon & click mouse
Review URL: https://codereview.chromium.org/
867803004
Cr-Commit-Position: refs/heads/master@{#313464}