Automated commit: libchrome r1463957 uprev

Merge with upstream commit 4ce7f6c9a5cc3eb1590a32db3c2374cef5772e0b

update BUILD.gn to add new file

BUG=None
TEST=sudo emerge libchrome

Disallow-Looks-For-Green: True
Change-Id: Ib056fc56a8ca6e1d27340e5dd7106076d19d46f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/libchrome/+/6575446
Reviewed-by: Ryo Hashimoto <[email protected]>
Commit-Queue: Ryo Hashimoto <[email protected]>
Reviewed-by: Di Wu <[email protected]>
Tested-by: Brett Brotherton <[email protected]>