Fix showing the sibling menu on mouse move

ash/display/screen_ash.cc

 // Copyright 2014 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 "ash/display/screen_ash.h"
 
 #include "ash/common/shelf/shelf_widget.h"
 #include "ash/common/wm/root_window_finder.h"
 #include "ash/common/wm_window.h"
 #include "ash/display/window_tree_host_manager.h"
@@ skipping 72 matching lines @@
 
 ScreenAsh::ScreenAsh() {}
 
 ScreenAsh::~ScreenAsh() {}
 
 gfx::Point ScreenAsh::GetCursorScreenPoint() {
   return aura::Env::GetInstance()->last_mouse_location();
 }
 
 bool ScreenAsh::IsWindowUnderCursor(gfx::NativeWindow window) {
-  return GetWindowAtScreenPoint(
-             display::Screen::GetScreen()->GetCursorScreenPoint()) == window;
+  return window->Contains(GetWindowAtScreenPoint(
+      display::Screen::GetScreen()->GetCursorScreenPoint()));
 }
 
 gfx::NativeWindow ScreenAsh::GetWindowAtScreenPoint(const gfx::Point& point) {
   aura::Window* root_window =
       WmWindow::GetAuraWindow(wm::GetRootWindowAt(point));
   aura::client::ScreenPositionClient* position_client =
       aura::client::GetScreenPositionClient(root_window);
 
   gfx::Point local_point = point;
   if (position_client)
     position_client->ConvertPointFromScreen(root_window, &local_point);
 
-  return root_window->GetTopWindowContainingPoint(local_point);
+  return root_window->GetEventHandlerForPoint(local_point);
 }
 
 int ScreenAsh::GetNumDisplays() const {
   return GetDisplayManager()->GetNumDisplays();
 }
 
 const std::vector<display::Display>& ScreenAsh::GetAllDisplays() const {
   return GetDisplayManager()->active_display_list();
 }
 
@@ skipping 71 matching lines @@
 }
 
 // static
 void ScreenAsh::CreateScreenForShutdown() {
   delete screen_for_shutdown;
   screen_for_shutdown = new ScreenForShutdown(display::Screen::GetScreen());
   display::Screen::SetScreenInstance(screen_for_shutdown);
 }
 
 }  // namespace ash