I get the following error when running some of browser tests, for example PPAPINaClTestDisallowedSockets.TCPServerSocketPrivateDisallowed:

ERROR:power_monitor_device_source_win.cc(71)] Cannot create windows on non-UI thread, power monitor disabled!

Looking at NaClBrokerMain, I can see that this function creates an IO message loop and then tries to create an instance of PowerMonitorSource, which on Windows requires the main message loop to be a UI one.

We should also check if the same issue exists in other Chrome processes. Browser is the only process with UI message loop on the main thread.

+bajones@chromium.org, do you know who would be a good owner for this bug?