There's a number of policy tests that run the policy test server with an empty temporary data directory (as provided by the default constructor of policy::LocalPolicyTestServer).

When executing these tests, the following warning message from the policy test server appears many times:

Failed to load policies from /tmp/.org.chromium.Chromium.xxxxxx/policy

This is caused by the code in the policy test server that assumes that there's always some config in the data dir, which is not the case when running from a temporary directory.

To clean up this, either some stub empty config has to be written by the C++ code, or the policy test server should be somehow notified about the absence of the config.