Revert of Moving coordinate conversion methods from ash/wm to ui/wm.

ash/wm/coordinate_conversion.h

Index: ash/wm/coordinate_conversion.h
diff --git a/ash/wm/coordinate_conversion.h b/ash/wm/coordinate_conversion.h
index aa4a84850b1907244a3699bf92d5691335a3440a..539e7c036b85dcc2dd232f0c0839ca9dfc2db703 100644
--- a/ash/wm/coordinate_conversion.h
+++ b/ash/wm/coordinate_conversion.h
@@ -28,6 +28,16 @@
 // the virtual scren coordinates.
 ASH_EXPORT aura::Window* GetRootWindowMatching(const gfx::Rect& rect);
 
+// Converts the |point| from a given |window|'s coordinates into the screen
+// coordinates.
+ASH_EXPORT void ConvertPointToScreen(const aura::Window* window,
+                                     gfx::Point* point);
+
+// Converts the |point| from the screen coordinates to a given |window|'s
+// coordinates.
+ASH_EXPORT void ConvertPointFromScreen(const aura::Window* window,
+                                       gfx::Point* point_in_screen);
+
 }  // namespace wm
 }  // namespace ash