[exp] ash: Ash in Mus.

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/display/display_manager.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/root_window_settings.h"
@@ skipping 112 matching lines @@
   return GetDisplayManager()->active_display_list();
 }
 
 gfx::Display ScreenAsh::GetDisplayNearestWindow(gfx::NativeView window) const {
   if (!window)
     return GetPrimaryDisplay();
   const aura::Window* root_window = window->GetRootWindow();
   if (!root_window)
     return GetPrimaryDisplay();
   const RootWindowSettings* rws = GetRootWindowSettings(root_window);
+  if (!rws)
+    return GetPrimaryDisplay();
   int64_t id = rws->display_id;
   // if id is |kInvaildDisplayID|, it's being deleted.
   DCHECK(id != gfx::Display::kInvalidDisplayID);
   if (id == gfx::Display::kInvalidDisplayID)
     return GetPrimaryDisplay();
 
   DisplayManager* display_manager = GetDisplayManager();
   // RootWindow needs Display to determine its device scale factor
   // for non desktop display.
   gfx::Display mirroring_display = display_manager->GetMirroringDisplayById(id);
@@ skipping 34 matching lines @@
 
 void ScreenAsh::RemoveObserver(gfx::DisplayObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 gfx::Screen* ScreenAsh::CloneForShutdown() {
   return new ScreenForShutdown(this);
 }
 
 }  // namespace ash