Add support for virtual displays

ui/display/chromeos/update_display_configuration_task.cc

Index: ui/display/chromeos/update_display_configuration_task.cc
diff --git a/ui/display/chromeos/update_display_configuration_task.cc b/ui/display/chromeos/update_display_configuration_task.cc
index 335c661bb1154a5ceee36528b667bf005cf17867..6b412714d8fb93c91214e60b6bd1bed2901e5d32 100644
--- a/ui/display/chromeos/update_display_configuration_task.cc
+++ b/ui/display/chromeos/update_display_configuration_task.cc
@@ -48,6 +48,11 @@ void UpdateDisplayConfigurationTask::OnDisplaysUpdated(
     const std::vector<DisplaySnapshot*>& displays) {
   cached_displays_ = displays;
 
+  // Add virtual displays after retrieving the physical displays from the NDD.
+  cached_displays_.insert(cached_displays_.end(),
+                          virtual_display_snapshots_.begin(),
+                          virtual_display_snapshots_.end());
+
   if (cached_displays_.size() > 1 && background_color_argb_)
     delegate_->SetBackgroundColor(background_color_argb_);