Revert of aura: Require explicit ownership of the Env instance.

ui/views_content_client/views_content_client_main_parts_desktop_aura.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 "content/shell/browser/shell_browser_context.h"
+#include "ui/aura/env.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/widget/desktop_aura/desktop_screen.h"
 #include "ui/views_content_client/views_content_client.h"
 #include "ui/views_content_client/views_content_client_main_parts_aura.h"
 
 namespace ui {
 
 namespace {
 
 class ViewsContentClientMainPartsDesktopAura
@@ skipping 13 matching lines @@
 
 ViewsContentClientMainPartsDesktopAura::ViewsContentClientMainPartsDesktopAura(
     const content::MainFunctionParams& content_params,
     ViewsContentClient* views_content_client)
     : ViewsContentClientMainPartsAura(content_params, views_content_client) {
 }
 
 void ViewsContentClientMainPartsDesktopAura::PreMainMessageLoopRun() {
   ViewsContentClientMainPartsAura::PreMainMessageLoopRun();
 
+  aura::Env::CreateInstance(true);
   gfx::Screen::SetScreenInstance(
       gfx::SCREEN_TYPE_NATIVE, views::CreateDesktopScreen());
 
   views_content_client()->task().Run(browser_context(), NULL);
 }
 
 }  // namespace
 
 // static
 ViewsContentClientMainParts* ViewsContentClientMainParts::Create(
     const content::MainFunctionParams& content_params,
     ViewsContentClient* views_content_client) {
   return new ViewsContentClientMainPartsDesktopAura(
       content_params, views_content_client);
 }
 
 }  // namespace ui