Detect and fix overlapping displays

ash/display/display_configuration_controller.cc

Index: ash/display/display_configuration_controller.cc
diff --git a/ash/display/display_configuration_controller.cc b/ash/display/display_configuration_controller.cc
index d65cdbb65af18f15bdb167f4f83d60da83399db5..2dac9593506ba6f68820df27c88383fc86bb79f5 100644
--- a/ash/display/display_configuration_controller.cc
+++ b/ash/display/display_configuration_controller.cc
@@ -153,7 +153,6 @@ bool DisplayConfigurationController::IsLimited() {
 
 void DisplayConfigurationController::SetDisplayLayoutImpl(
     std::unique_ptr<display::DisplayLayout> layout) {
-  // TODO(oshima/stevenjb): Add support for 3+ displays.
   display_manager_->SetLayoutForCurrentDisplays(std::move(layout));
   if (display_animator_)
     display_animator_->StartFadeInAnimation();