Skip UpdateShadow if the surface has already been destroyed

components/exo/shell_surface.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/shell_surface.h"
 
 #include <algorithm>
 
 #include "ash/common/frame/custom_frame_view_ash.h"
 #include "ash/common/shelf/wm_shelf.h"
@@ skipping 1400 matching lines @@
   gfx::Rect client_view_bounds =
       widget_->non_client_view()->frame_view()->GetBoundsForClientView();
 
   // A change to the widget size requires surface bounds to be re-adjusted.
   surface_->window()->SetBounds(
       gfx::Rect(GetSurfaceOrigin() + client_view_bounds.OffsetFromOrigin(),
                 surface_->window()->layer()->size()));
 }
 
 void ShellSurface::UpdateShadow() {
-  if (!widget_)
+  if (!widget_ || !surface_)
     return;
   aura::Window* window = widget_->GetNativeWindow();
   if (!shadow_enabled_) {
     wm::SetShadowElevation(window, wm::ShadowElevation::NONE);
     if (shadow_underlay_)
       shadow_underlay_->Hide();
   } else {
     wm::SetShadowElevation(window, wm::ShadowElevation::MEDIUM);
     gfx::Rect shadow_content_bounds =
         gfx::ScaleToEnclosedRect(shadow_content_bounds_, 1.f / scale_);
@@ skipping 111 matching lines @@
     // small style shadow for them.
     if (!activatable_)
       shadow->SetElevation(wm::ShadowElevation::SMALL);
     // We don't have rounded corners unless frame is enabled.
     if (!frame_enabled_)
       shadow->SetRoundedCornerRadius(0);
   }
 }
 
 }  // namespace exo