eclass-overlay: create new user shadercached

This user will be running the new host daemon, shadercached. See
go/borealis-shader-client-design for further details.

BUG=b:243081664
TEST=Not applicable

Change-Id: Iaaa3f615fada1d2a532c2f5ca9a6f4fa1cc56c7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/eclass-overlay/+/3858248
Tested-by: Max Lee <endlesspring@google.com>
Reviewed-by: Allen Webb <allenwebb@google.com>
Commit-Queue: Max Lee <endlesspring@google.com>
diff --git a/profiles/base/accounts/group/shadercached b/profiles/base/accounts/group/shadercached
new file mode 100644
index 0000000..5a88fbf
--- /dev/null
+++ b/profiles/base/accounts/group/shadercached
@@ -0,0 +1,4 @@
+group:shadercached
+password:!
+gid:333
+users:shadercached
diff --git a/profiles/base/accounts/user/shadercached b/profiles/base/accounts/user/shadercached
new file mode 100644
index 0000000..a68ee74
--- /dev/null
+++ b/profiles/base/accounts/user/shadercached
@@ -0,0 +1,6 @@
+user:shadercached
+uid:333
+gid:333
+gecos:VM shader cache management user
+home:/dev/null
+shell:/bin/false