The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/17e044d3ebd808102a1e23b610c812482265976e

commit 17e044d3ebd808102a1e23b610c812482265976e
Author: James Cook <jamescook@chromium.org>
Date: Mon Aug 13 03:37:20 2018

Collapse ash::TabletModeEventHandler with TabletModeEventHandlerClassic

There's no separate "classic" mode in ash anymore. Collapse the
superclass with its only subclass.

Just cleanup, no functional changes.

Bug:  873267 
Test: ash_unittests
Change-Id: I8d4243ad50d66ac7982dbe12132a736903271f63
Reviewed-on: https://chromium-review.googlesource.com/1171807
Reviewed-by: Jun Mukai <mukai@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582498}
[modify] https://crrev.com/17e044d3ebd808102a1e23b610c812482265976e/ash/BUILD.gn
[modify] https://crrev.com/17e044d3ebd808102a1e23b610c812482265976e/ash/wm/tablet_mode/tablet_mode_event_handler.cc
[modify] https://crrev.com/17e044d3ebd808102a1e23b610c812482265976e/ash/wm/tablet_mode/tablet_mode_event_handler.h
[delete] https://crrev.com/80d06f065940ba91618bcfebfc22332ccfb60081/ash/wm/tablet_mode/tablet_mode_event_handler_classic.cc
[delete] https://crrev.com/80d06f065940ba91618bcfebfc22332ccfb60081/ash/wm/tablet_mode/tablet_mode_event_handler_classic.h
[modify] https://crrev.com/17e044d3ebd808102a1e23b610c812482265976e/ash/wm/tablet_mode/tablet_mode_window_manager.cc