Add display task to trigger display configuration

ui/display/types/native_display_delegate.h

Index: ui/display/types/native_display_delegate.h
diff --git a/ui/display/types/native_display_delegate.h b/ui/display/types/native_display_delegate.h
index 7bf7b6befd9a66e23e764ee6849b5eae32465fcb..1f542c61772e12d0209c41a4dca8dde12ddcc73a 100644
--- a/ui/display/types/native_display_delegate.h
+++ b/ui/display/types/native_display_delegate.h
@@ -24,6 +24,8 @@ class DisplaySnapshot;
 
 class NativeDisplayObserver;
 
+typedef base::Callback<void(const std::vector<ui::DisplaySnapshot*>&)>
+    GetDisplaysCallback;
 typedef base::Callback<void(bool)> ConfigureCallback;
 
 // Interface for classes that perform display configuration actions on behalf
@@ -62,6 +64,8 @@ class DISPLAY_TYPES_EXPORT NativeDisplayDelegate {
   // pointers.
   virtual std::vector<ui::DisplaySnapshot*> GetDisplays() = 0;
 
+  virtual void GetDisplays(const GetDisplaysCallback& callback) = 0;
+
   // Adds |mode| to |output|. |mode| must be a valid display mode pointer.
   virtual void AddMode(const ui::DisplaySnapshot& output,
                        const ui::DisplayMode* mode) = 0;