libchrome: install header to unversioned path.

Install header to /usr/include/libchrome.

Also, keep a symlink at /usr/include/base-$BASE_VER pointing to
libchrome for backward compatibility.

BUG=chromium:920513
TEST=emerge libchrome; equery files libchrome

Change-Id: Ibeccc63bb83d26444b4cbfdee027fb476193deff
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2586584
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Tested-by: Qijiang Fan <fqj@google.com>
Commit-Queue: Qijiang Fan <fqj@google.com>
1 file changed