Only display the splash screen on the main monitor.

Before this change, we always displayed the splash screen on all
connected monitors. When their resolutions mismatch, this looks ugly.

As per bug chromium-os:34066, we now want the splash screen to only
display on one monitor. To do that, we call into the KMS API to probe
the monitor state, pick a main monitor (LVDS, eDP, or the first
connected one we find), and disable all non-main monitors.

This behaviour is the default, and can be disabled with the new
--no-set-monitors flag.

TEST=by hand, the splash screen only happens on the main monitor.

Change-Id: I63803311f41a64f3ab26c54a4d72bfe0dd2b374d
Reviewed-by: Stéphane Marchesin <>
Tested-by: Stéphane Marchesin <>
Commit-Ready: Stéphane Marchesin <>
10 files changed