Clean up IApplicaitonLifetime service injection.

src/Microsoft.AspNet.Hosting/HostingContext.cs

@@ -27,7 +27,6 @@ namespace Microsoft.AspNet.Hosting
     {
         public IServiceProvider Services { get; set; }
         public IConfiguration Configuration { get; set; }
-        public ApplicationLifetime Lifetime { get; set; }
 
         public IBuilder Builder { get; set; }
 

src/Microsoft.AspNet.Hosting/HostingEngine.cs

@@ -46,35 +46,24 @@ namespace Microsoft.AspNet.Hosting
 
         public IDisposable Start(HostingContext context)
         {
-            EnsureLifetime(context);
             EnsureBuilder(context);
             EnsureServerFactory(context);
             InitalizeServerFactory(context);
             EnsureApplicationDelegate(context);
 
+            var applicationLifetime = (ApplicationLifetime)context.Services.GetService<IApplicationLifetime>();
             var pipeline = new PipelineInstance(_httpContextFactory, context.ApplicationDelegate);
             var server = context.ServerFactory.Start(context.Server, pipeline.Invoke);
            
             return new Disposable(() =>
             {
-                context.Lifetime.SignalStopping();
+                applicationLifetime.SignalStopping();
                 server.Dispose();
-                context.Lifetime.SignalStopped();
                 pipeline.Dispose();
+                applicationLifetime.SignalStopped();
             });
         }
 
-        private void EnsureLifetime(HostingContext context)
-        {
-            if (context.Lifetime == null)
-            {
-                context.Lifetime = new ApplicationLifetime();
-            }
-            var serviceCollection = new ServiceCollection();
-            serviceCollection.AddInstance<IApplicationLifetime>(context.Lifetime);
-            context.Services = serviceCollection.BuildServiceProvider(context.Services);
-        }
-
         private void EnsureBuilder(HostingContext context)
         {
             if (context.Builder != null)

src/Microsoft.AspNet.Hosting/HostingServices.cs

@@ -49,6 +49,8 @@ namespace Microsoft.AspNet.Hosting
 
             yield return describer.Transient<ITypeActivator, TypeActivator>();
 
+            yield return describer.Instance<IApplicationLifetime>(new ApplicationLifetime());
+
             // TODO: We expect this to be provide by the runtime eventually.
             yield return describer.Instance<ILoggerFactory>(new NullLoggerFactory());
 

src/Microsoft.AspNet.Hosting/Program.cs

@@ -84,7 +84,7 @@ namespace Microsoft.AspNet.Hosting
                 shutdownHandle.Set();
             });
 
-            Task ignored = Task.Run(() =>
+            var ignored = Task.Run(() =>
             {
                 Console.WriteLine("Started");
                 Console.ReadLine();