Automated commit: libchrome r1506375 uprev

Merge with upstream commit 30301827d8aea84a98ed63e791ad8e39e6d22183

BUG=None
TEST=sudo emerge libchrome

Change-Id: I983f980c6526800dfceb403dfdd77144a28606f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/libchrome/+/6884881
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Commit-Queue: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Bot-Commit: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>