EXO: Move WaylandInputDelegate out of server.cc

Include wayland_input_delegate.h in server.cc until a later CL,
this is needed for classes in server.cc that inherit from it.

Bug: 896710
Test: Build ChromeOS
Change-Id: I668280ccceab8a9e75874247919d0d0b3fea1cb1
Reviewed-on: https://chromium-review.googlesource.com/c/1316100
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@{#608035}
4 files changed