aura: Require explicit ownership of the Env instance.

ui/aura/env.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/env.h"
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
 #include "base/threading/thread_local.h"
 #include "ui/aura/env_observer.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/events/event_target_iterator.h"
 #include "ui/events/platform/platform_event_source.h"
 
 #if defined(USE_OZONE)
 #include "ui/ozone/public/ozone_platform.h"
 #endif
 
 namespace aura {
 
 namespace {
 
 // Env is thread local so that aura may be used on multiple threads.
 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:
 
-// static
-void Env::CreateInstance(bool create_event_source) {
-  if (!lazy_tls_ptr.Pointer()->Get())
-    (new Env())->Init(create_event_source);
+Env::~Env() {
+  FOR_EACH_OBSERVER(EnvObserver, observers_, OnWillDestroyEnv());
+  DCHECK_EQ(this, lazy_tls_ptr.Pointer()->Get());
+  lazy_tls_ptr.Pointer()->Set(NULL);
 }
 
 // static
+std::unique_ptr<Env> Env::CreateInstance() {
+  DCHECK(!lazy_tls_ptr.Pointer()->Get());
+  std::unique_ptr<Env> env(new Env());
+  env->Init();
+  return env;
+}
+
+// static
 Env* Env::GetInstance() {
   Env* env = lazy_tls_ptr.Pointer()->Get();
   DCHECK(env) << "Env::CreateInstance must be called before getting the "
                  "instance of Env.";
   return env;
 }
 
 // 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) {
   observers_.AddObserver(observer);
 }
 
 void Env::RemoveObserver(EnvObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 bool Env::IsMouseButtonDown() const {
   return input_state_lookup_.get() ? input_state_lookup_->IsMouseButtonDown() :
       mouse_button_flags_ != 0;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Env, private:
 
 Env::Env()
     : mouse_button_flags_(0),
       is_touch_down_(false),
       input_state_lookup_(InputStateLookup::Create()),
       context_factory_(NULL) {
   DCHECK(lazy_tls_ptr.Pointer()->Get() == NULL);
   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();
 }
 
 void Env::NotifyWindowInitialized(Window* window) {
   FOR_EACH_OBSERVER(EnvObserver, observers_, OnWindowInitialized(window));
 }
 
 void Env::NotifyHostInitialized(WindowTreeHost* host) {
@@ skipping 18 matching lines @@
 scoped_ptr<ui::EventTargetIterator> Env::GetChildIterator() const {
   return nullptr;
 }
 
 ui::EventTargeter* Env::GetEventTargeter() {
   NOTREACHED();
   return NULL;
 }
 
 }  // namespace aura