Fix showing the sibling menu on mouse move

ui/aura/test/test_screen.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/test/test_screen.h"
 
 #include <stdint.h>
 
 #include "base/logging.h"
 #include "ui/aura/env.h"
@@ skipping 135 matching lines @@
   return Env::GetInstance()->last_mouse_location();
 }
 
 bool TestScreen::IsWindowUnderCursor(gfx::NativeWindow window) {
   return GetWindowAtScreenPoint(GetCursorScreenPoint()) == window;
 }
 
 gfx::NativeWindow TestScreen::GetWindowAtScreenPoint(const gfx::Point& point) {
   if (!host_ || !host_->window())
     return nullptr;
-  return host_->window()->GetTopWindowContainingPoint(point);
+  return host_->window()->GetEventHandlerForPoint(point);
 }
 
 display::Display TestScreen::GetDisplayNearestWindow(
     gfx::NativeWindow window) const {
   return GetPrimaryDisplay();
 }
 
 TestScreen::TestScreen(const gfx::Rect& screen_bounds,
                        WindowTreeClient* window_tree_client)
     : host_(nullptr), ui_scale_(1.0f), window_tree_client_(window_tree_client) {
   static int64_t synthesized_display_id = 2000;
   display::Display display(synthesized_display_id++);
   display.SetScaleAndBounds(1.0f, screen_bounds);
   ProcessDisplayChanged(display, true /* is_primary */);
 }
 
 }  // namespace aura