aura: Require explicit ownership of the Env instance.

ui/aura/test/run_all_unittests.cc

Index: ui/aura/test/run_all_unittests.cc
diff --git a/ui/aura/test/run_all_unittests.cc b/ui/aura/test/run_all_unittests.cc
index 0e7ff20c6958efa3a4f4d258b2b8be554fbbcc3e..1e6de4aa5ff6f3bddcebd903a96af15227a0db45 100644
--- a/ui/aura/test/run_all_unittests.cc
+++ b/ui/aura/test/run_all_unittests.cc
@@ -18,15 +18,16 @@ class AuraTestSuite : public base::TestSuite {
   void Initialize() override {
     base::TestSuite::Initialize();
     gfx::GLSurfaceTestSupport::InitializeOneOff();
-    aura::Env::CreateInstance(true);
+    env_ = aura::Env::CreateInstance();
   }
 
   void Shutdown() override {
-    aura::Env::DeleteInstance();
+    env_.reset();
     base::TestSuite::Shutdown();
   }
 
  private:
+  std::unique_ptr<aura::Env> env_;
   DISALLOW_COPY_AND_ASSIGN(AuraTestSuite);
 };