Moves FindDisplayIndexContainingPoint into display

ui/display/manager/display_manager_utilities.cc

Index: ui/display/manager/display_manager_utilities.cc
diff --git a/ui/display/manager/display_manager_utilities.cc b/ui/display/manager/display_manager_utilities.cc
index 5ec37b409a235720389cb8cadcd14f1b408eb62a..af1c42d5bcb0d786163cbdba6d62a26e1f74447e 100644
--- a/ui/display/manager/display_manager_utilities.cc
+++ b/ui/display/manager/display_manager_utilities.cc
@@ -266,15 +266,6 @@ bool ComputeBoundary(const Display& a_display,
   return true;
 }
 
-int FindDisplayIndexContainingPoint(const std::vector<Display>& displays,
-                                    const gfx::Point& point_in_screen) {
-  auto iter = std::find_if(displays.begin(), displays.end(),
-                           [point_in_screen](const Display& display) {
-                             return display.bounds().Contains(point_in_screen);
-                           });
-  return iter == displays.end() ? -1 : (iter - displays.begin());
-}
-
 DisplayIdList CreateDisplayIdList(const Displays& list) {
   return GenerateDisplayIdList(
       list.begin(), list.end(),