Running linux-chromeos with DCHECK enabled:
1. Enable mirror mode (ctrl-f4 or in the Settings UI)
2. Rotate the displays (ctrl-shift-f3, it does not work in the current Settings UI in mirror mode)
3. Disable mirror more (ctrl-f4 or in the Settings UI)

Crash:

[4247:4247:0407/095835:FATAL:display_util.cc(399)] Check failed: id1 != id2 (2200000001 vs. 2200000001)
#0 0x7f5a1a56541e base::debug::StackTrace::StackTrace()
#1 0x7f5a1a581c0a logging::LogMessage::~LogMessage()
#2 0x7f5a159eff98 ash::CompareDisplayIds()
#3 0x7f5a159ed10b std::__unguarded_linear_insert<>()
#4 0x7f5a159ed0b8 std::__insertion_sort<>()
#5 0x7f5a159e6b41 ash::DisplayManager::UpdateDisplaysWith()
#6 0x7f5a159e8401 ash::DisplayManager::ReconfigureDisplays()
#7 0x7f5a159ee201 ash::DisplayConfigurationController::SetMirrorModeImpl()