EXO: Refactored cursor_shapes interface

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

Bug: 896710
Test: Built on ChromeOS
Change-Id: I43f93d25bf08f57d0f111ba99404a1fecb3723da
Reviewed-on: https://chromium-review.googlesource.com/c/1324139
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@{#608970}
4 files changed