Minimize black screen during the boot with multi displays

chromeos/display/output_configurator.h

Index: chromeos/display/output_configurator.h
diff --git a/chromeos/display/output_configurator.h b/chromeos/display/output_configurator.h
index e1b42a8220fe080b1e1972a11c825191b5d05200..4c729298dc906990714f1a02dad16b24c86fb8a7 100644
--- a/chromeos/display/output_configurator.h
+++ b/chromeos/display/output_configurator.h
@@ -71,7 +71,10 @@ class CHROMEOS_EXPORT OutputConfigurator : public MessageLoop::Dispatcher {
 
   // Initialization, must be called right after constructor.
   // |is_panel_fitting_enabled| indicates hardware panel fitting support.
-  void Init(bool is_panel_fitting_enabled);
+  // If |background_color_argb| is non zero and there are multiple displays,
+  // OutputConfigurator sets the background color of X's RootWindow to this
+  // color.
+  void Init(bool is_panel_fitting_enabled, uint32 background_color_argb);
 
   // Called when the user hits ctrl-F4 to request a display mode change.
   // This method should only return false if it was called in a single-head or