Add cryptohome user for the cryptohome service.

Creates a cryptohome user, and group, for cryptohome to run as.

BUG=chromium:741786
TEST=emerge-${BOARD} cryptohome

Change-Id: Idf12a097e072cea51e0dc53998b93ae0578c9afc
Reviewed-on: https://chromium-review.googlesource.com/569182
Commit-Ready: Matthew Denton <mpdenton@google.com>
Tested-by: Greg Kerr <kerrnel@chromium.org>
Tested-by: Matthew Denton <mpdenton@google.com>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/profiles/base/accounts/group/cryptohome b/profiles/base/accounts/group/cryptohome
new file mode 100644
index 0000000..cba6056
--- /dev/null
+++ b/profiles/base/accounts/group/cryptohome
@@ -0,0 +1,2 @@
+group:cryptohome
+gid:292
diff --git a/profiles/base/accounts/user/cryptohome b/profiles/base/accounts/user/cryptohome
new file mode 100644
index 0000000..6622e22
--- /dev/null
+++ b/profiles/base/accounts/user/cryptohome
@@ -0,0 +1,6 @@
+user:cryptohome
+uid:292
+gid:292
+gecos:cryptohome service and client
+home:/dev/null
+shell:/bin/false