aura: Require explicit ownership of the Env instance.

chromecast/browser/cast_browser_main_parts.cc

Index: chromecast/browser/cast_browser_main_parts.cc
diff --git a/chromecast/browser/cast_browser_main_parts.cc b/chromecast/browser/cast_browser_main_parts.cc
index f07ca2628502032e30290bebf1fc2294292bfd99..e904f784305cee5ceb7a00f8d04e1e30411fe160 100644
--- a/chromecast/browser/cast_browser_main_parts.cc
+++ b/chromecast/browser/cast_browser_main_parts.cc
@@ -79,7 +79,6 @@
 // header, but is exported to allow injecting the overlay-composited
 // callback.
 #include "chromecast/graphics/cast_screen.h"
-#include "ui/aura/env.h"
 #include "ui/gfx/screen.h"
 #include "ui/ozone/platform/cast/overlay_manager_cast.h"  // nogncheck
 #endif
@@ -485,10 +484,6 @@ void CastBrowserMainParts::PostMainMessageLoopRun() {
   cast_browser_process_->metrics_service_client()->Finalize();
   cast_browser_process_.reset();
 
-#if defined(USE_AURA)
-  aura::Env::DeleteInstance();
-#endif
-
   DeregisterKillOnAlarm();
 #endif
 }