Fix using WM_POINTER instead of WM_TOUCH

- Add runtime setting to disable/enable WM_POINTER for touch. Defaults
  to disabled in this patch. Will be enabled as a followup change.
- Fix min/max/exit buttons for touch. For unhandled events do a hit test
  and check if they are in the client area. If they are mark them as
  handled as we don't want windows to send us compatibility events if
  we've already dispatched them from the pointer events.
- Set the last_touch_or_pen_message_time for touch events via WM_POINTER.

BUG=792892,763223

Change-Id: I4350c7e84f96271b9ec27119815bf37a9461d489
Reviewed-on: https://chromium-review.googlesource.com/911752
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#535925}
5 files changed