Hide DeviceMode from X11 headers

X11 headers create a lot of macros using fairly normal names which
causes collisions in code that was written without X11 headers in
mind.

DeviceMode is also a type in components/policy and if that and
X11 includes end up in the same translation unit, there will be
compilation errors.

This was encountered in non-standard jumbo configurations and will
not affect currently supported code.

Bug: 782184
Change-Id: I84f9874d2858fc60c7e7c0e017d028dc8b710661
Reviewed-on: https://chromium-review.googlesource.com/847577
Reviewed-by: Dan Erat <derat@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#526524}
1 file changed