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 7e82d4e13cdba8de340959236efcea0cff0e1c4d..672f4db8b026d73066293a633eb2a80796fbf03e 100644
--- a/ui/aura/env.cc
+++ b/ui/aura/env.cc
@@ -24,23 +24,29 @@ namespace {
 base::LazyInstance<base::ThreadLocalPointer<Env> >::Leaky lazy_tls_ptr =
     LAZY_INSTANCE_INITIALIZER;
 
-#if defined(USE_OZONE)
 // Returns true if running inside of mus. Checks for mojo specific flag.
 bool RunningInsideMus() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       "primordial-pipe-token");
 }
-#endif
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // 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
-void Env::CreateInstance(bool create_event_source) {
-  if (!lazy_tls_ptr.Pointer()->Get())
-    (new Env())->Init(create_event_source);
+std::unique_ptr<Env> Env::CreateInstance() {
+  DCHECK(!lazy_tls_ptr.Pointer()->Get());
+  std::unique_ptr<Env> env(new Env());
+  env->Init();
+  return env;
 }
 
 // static
@@ -56,11 +62,6 @@ Env* Env::GetInstanceDontCreate() {
   return lazy_tls_ptr.Pointer()->Get();
 }
 
-// static
-void Env::DeleteInstance() {
-  delete lazy_tls_ptr.Pointer()->Get();
-}
-
 void Env::AddObserver(EnvObserver* observer) {
   observers_.AddObserver(observer);
 }
@@ -86,21 +87,14 @@ Env::Env()
   lazy_tls_ptr.Pointer()->Set(this);
 }
 
-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 (!create_event_source)
+void Env::Init() {
+  if (RunningInsideMus())
     return;
 #if defined(USE_OZONE)
   // The ozone platform can provide its own event source. So initialize the
   // platform before creating the default event source. If running inside mus
   // let the mus process initialize ozone instead.
-  if (!RunningInsideMus())
-    ui::OzonePlatform::InitializeForUI();
+  ui::OzonePlatform::InitializeForUI();
 #endif
   if (!ui::PlatformEventSource::GetInstance())
     event_source_ = ui::PlatformEventSource::CreateDefault();