mus: aura::Env should be destroyed last in the mus client.

chrome/browser/ui/views/chrome_browser_main_extra_parts_views_linux.cc

 // Copyright 2016 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 "chrome/browser/ui/views/chrome_browser_main_extra_parts_views_linux.h"
 
 #include "base/run_loop.h"
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/themes/theme_service.h"
@@ skipping 48 matching lines @@
   return ui::NativeTheme::GetInstanceForNativeUi();
 }
 
 }  // namespace
 
 ChromeBrowserMainExtraPartsViewsLinux::ChromeBrowserMainExtraPartsViewsLinux() {
 }
 
 ChromeBrowserMainExtraPartsViewsLinux::
     ~ChromeBrowserMainExtraPartsViewsLinux() {
-  // X11DesktopHandler is destructed at this point, so we don't need to remove
-  // ourselves as an X11DesktopHandlerObserver
-  DCHECK(!aura::Env::GetInstanceDontCreate());
+  views::X11DesktopHandler::get()->RemoveObserver(this);
 }
 
 void ChromeBrowserMainExtraPartsViewsLinux::PreEarlyInitialization() {
   // TODO(erg): Refactor this into a dlopen call when we add a GTK3 port.
   views::LinuxUI* gtk2_ui = BuildGtk2UI();
   gtk2_ui->SetNativeThemeOverride(base::Bind(&GetNativeThemeForWindow));
   views::LinuxUI::SetInstance(gtk2_ui);
 }
 
 void ChromeBrowserMainExtraPartsViewsLinux::ToolkitInitialized() {
   ChromeBrowserMainExtraPartsViews::ToolkitInitialized();
   views::LinuxUI::instance()->Initialize();
 }
 
 void ChromeBrowserMainExtraPartsViewsLinux::PreCreateThreads() {
   // Update the device scale factor before initializing views
   // because its display::Screen instance depends on it.
   views::LinuxUI::instance()->UpdateDeviceScaleFactor();
   ChromeBrowserMainExtraPartsViews::PreCreateThreads();
   views::X11DesktopHandler::get()->AddObserver(this);
 }
 
 void ChromeBrowserMainExtraPartsViewsLinux::OnWorkspaceChanged(
     const std::string& new_workspace) {
   BrowserList::MoveBrowsersInWorkspaceToFront(new_workspace);
 }