Add ScreenPositionClient::ConvertNativePointToScreen.

ash/display/screen_position_controller.cc

Index: ash/display/screen_position_controller.cc
diff --git a/ash/display/screen_position_controller.cc b/ash/display/screen_position_controller.cc
index c453c7bd5a26d3151286c944d9c9aad887c6fe73..aad39cd4ed356e38a17092c25641184c5d896145 100644
--- a/ash/display/screen_position_controller.cc
+++ b/ash/display/screen_position_controller.cc
@@ -8,6 +8,7 @@
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
+#include "ash/wm/coordinate_conversion.h"
 #include "ash/wm/system_modal_container_layout_manager.h"
 #include "ash/wm/window_properties.h"
 #include "ash/wm/workspace_controller.h"
@@ -76,6 +77,15 @@ void ScreenPositionController::ConvertPointFromScreen(
   aura::Window::ConvertPointToTarget(root, window, point);
 }
 
+void ScreenPositionController::ConvertNativePointToScreen(
+    aura::Window* window,
+    gfx::Point* point) {
+  std::pair<aura::RootWindow*, gfx::Point> pair =
+      wm::GetRootWindowRelativeToWindow(window, *point);
+  *point = pair.second;
+  ConvertPointToScreen(pair.first, point);
+}
+
 void ScreenPositionController::SetBounds(aura::Window* window,
                                          const gfx::Rect& bounds,
                                          const gfx::Display& display) {