exo: Fix multi-display cursor crash

components/exo/pointer.cc

Index: components/exo/pointer.cc
diff --git a/components/exo/pointer.cc b/components/exo/pointer.cc
index fe25e944589c979ca614ba3fbbd30170ab05c15f..3f4227a39a03b49444eebc6a941a414abb23494b 100644
--- a/components/exo/pointer.cc
+++ b/components/exo/pointer.cc
@@ -89,9 +89,8 @@ void Pointer::SetCursor(Surface* surface, const gfx::Point& hotspot) {
     }
     if (surface_) {
       surface_->window()->SetTransform(gfx::Transform());
-      WMHelper::GetInstance()
-          ->GetContainer(ash::kShellWindowId_MouseCursorContainer)
-          ->RemoveChild(surface_->window());
+      if (surface_->window()->parent())
+        surface_->window()->parent()->RemoveChild(surface_->window());
       surface_->SetSurfaceDelegate(nullptr);
       surface_->RemoveSurfaceObserver(this);
     }