EXO: Refactor WaylandTouchDelegate into its own file

Move WaylandTouchDelegate out of server.cc
This CL only moves code around.

Bug: 896710
Test: Built on ChromeOS
Change-Id: I8fc2cb3d52c76bdcc4d52c70e63beeb6cd403894
Reviewed-on: https://chromium-review.googlesource.com/c/1318737
Commit-Queue: Shawn Gallea <sagallea@google.com>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608211}
4 files changed