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

ui/views_content_client/views_content_client_main_parts_desktop_aura.cc

Index: ui/views_content_client/views_content_client_main_parts_desktop_aura.cc
diff --git a/ui/views_content_client/views_content_client_main_parts_desktop_aura.cc b/ui/views_content_client/views_content_client_main_parts_desktop_aura.cc
index db328bd46413901fdf711479c53f8320b1b876ad..93401e607b51a916157996a439c722b5b2ee0add 100644
--- a/ui/views_content_client/views_content_client_main_parts_desktop_aura.cc
+++ b/ui/views_content_client/views_content_client_main_parts_desktop_aura.cc
@@ -3,6 +3,7 @@
 // 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"
@@ -36,6 +37,7 @@
 void ViewsContentClientMainPartsDesktopAura::PreMainMessageLoopRun() {
   ViewsContentClientMainPartsAura::PreMainMessageLoopRun();
 
+  aura::Env::CreateInstance(true);
   gfx::Screen::SetScreenInstance(
       gfx::SCREEN_TYPE_NATIVE, views::CreateDesktopScreen());