exo: Fix crash in SetCursor

components/exo/pointer.cc

 // Copyright 2015 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 "components/exo/pointer.h"
 
 #include "ash/common/shell_window_ids.h"
 #include "ash/display/display_manager.h"
 #include "components/exo/pointer_delegate.h"
 #include "components/exo/pointer_stylus_delegate.h"
@@ skipping 54 matching lines @@
   auto* helper = WMHelper::GetInstance();
   helper->RemoveCursorObserver(this);
   helper->RemovePreTargetHandler(this);
 }
 
 void Pointer::SetCursor(Surface* surface, const gfx::Point& hotspot) {
   // Early out if the pointer doesn't have a surface in focus.
   if (!focus_)
     return;
 
+  if (!widget_)
+    CreatePointerWidget();
+
   // If surface is different than the current pointer surface then remove the
   // current surface and add the new surface.
   if (surface != surface_) {
     if (surface && surface->HasSurfaceDelegate()) {
       DLOG(ERROR) << "Surface has already been assigned a role";
       return;
     }
     if (surface_) {
       widget_->GetNativeWindow()->RemoveChild(surface_->window());
       surface_->window()->Hide();
@@ skipping 277 matching lines @@
 
   if (ui_scale != cursor_scale_) {
     gfx::Transform transform;
     transform.Scale(ui_scale, ui_scale);
     widget_->GetNativeWindow()->SetTransform(transform);
     cursor_scale_ = ui_scale;
   }
 }
 
 }  // namespace exo