aura: Require explicit ownership of the Env instance.

ui/views_content_client/views_content_client_main_parts_aura.cc

Index: ui/views_content_client/views_content_client_main_parts_aura.cc
diff --git a/ui/views_content_client/views_content_client_main_parts_aura.cc b/ui/views_content_client/views_content_client_main_parts_aura.cc
index 5e1c69a295bb27710548d40df77ead1b2dd87da7..fecc44d6655038e361e68ffb6b0f444ea05bb30b 100644
--- a/ui/views_content_client/views_content_client_main_parts_aura.cc
+++ b/ui/views_content_client/views_content_client_main_parts_aura.cc
@@ -4,7 +4,6 @@
 
 #include "ui/views_content_client/views_content_client_main_parts_aura.h"
 
-#include "ui/aura/env.h"
 #include "ui/wm/core/wm_state.h"
 
 namespace ui {
@@ -25,8 +24,6 @@ void ViewsContentClientMainPartsAura::ToolkitInitialized() {
 }
 
 void ViewsContentClientMainPartsAura::PostMainMessageLoopRun() {
-  aura::Env::DeleteInstance();
-
   ViewsContentClientMainParts::PostMainMessageLoopRun();
 }