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

ui/aura/env.cc

Index: ui/aura/env.cc
diff --git a/ui/aura/env.cc b/ui/aura/env.cc
index 0130bcbbe0f3f77e6f9f41d31d47fae3f0f1cd36..4d2db40d6f1cd33136a5ce42d450a142cc8767e2 100644
--- a/ui/aura/env.cc
+++ b/ui/aura/env.cc
@@ -28,18 +28,10 @@
 ////////////////////////////////////////////////////////////////////////////////
 // Env, public:
 
-Env::~Env() {
-  FOR_EACH_OBSERVER(EnvObserver, observers_, OnWillDestroyEnv());
-  DCHECK_EQ(this, lazy_tls_ptr.Pointer()->Get());
-  lazy_tls_ptr.Pointer()->Set(NULL);
-}
-
 // static
-scoped_ptr<Env> Env::CreateInstance() {
-  DCHECK(!lazy_tls_ptr.Pointer()->Get());
-  scoped_ptr<Env> env(new Env());
-  env->Init();
-  return env.Pass();
+void Env::CreateInstance(bool create_event_source) {
+  if (!lazy_tls_ptr.Pointer()->Get())
+    (new Env())->Init(create_event_source);
 }
 
 // static
@@ -53,6 +45,11 @@
 // static
 Env* Env::GetInstanceDontCreate() {
   return lazy_tls_ptr.Pointer()->Get();
+}
+
+// static
+void Env::DeleteInstance() {
+  delete lazy_tls_ptr.Pointer()->Get();
 }
 
 void Env::AddObserver(EnvObserver* observer) {
@@ -80,13 +77,19 @@
   lazy_tls_ptr.Pointer()->Set(this);
 }
 
-void Env::Init() {
+Env::~Env() {
+  FOR_EACH_OBSERVER(EnvObserver, observers_, OnWillDestroyEnv());
+  DCHECK_EQ(this, lazy_tls_ptr.Pointer()->Get());
+  lazy_tls_ptr.Pointer()->Set(NULL);
+}
+
+void Env::Init(bool create_event_source) {
 #if defined(USE_OZONE)
   // The ozone platform can provide its own event source. So initialize the
   // platform before creating the default event source.
   ui::OzonePlatform::InitializeForUI();
 #endif
-  if (!ui::PlatformEventSource::GetInstance())
+  if (create_event_source && !ui::PlatformEventSource::GetInstance())
     event_source_ = ui::PlatformEventSource::CreateDefault();
 }