Allow MEF to find UsageTracker.

Author: grokys

src/GitHub.App/Services/UsageTracker.cs

@@ -15,8 +15,11 @@
 using ReactiveUI;
 using Rothko;
 
+#pragma warning disable CS0649
+
 namespace GitHub.Services
 {
+    using Microsoft.VisualStudio.Shell;
     using Guard = GitHub.Extensions.Guard;
 
     [Export(typeof(IUsageTracker))]
@@ -67,16 +70,8 @@ public UsageTracker(
             ////Lazy<IAppVersionProvider> appVersionProvider,
             Lazy<IEnvironment> environment,
             IPackageSettings userSettings,
-            IServiceProvider serviceProvider)
+            IUIProvider serviceProvider)
         {
-            Guard.ArgumentNotNull(cache, "cache");
-            ////Guard.ArgumentNotNull(trackedRepositories, "trackedRepositories");
-            Guard.ArgumentNotNull(repositoryHosts, "repositoryHosts");
-            ////Guard.ArgumentNotNull(appVersionProvider, "appVersionProvider");
-            Guard.ArgumentNotNull(environment, "environment");
-            Guard.ArgumentNotNull(userSettings, "userSettings");
-            Guard.ArgumentNotNull(serviceProvider, "serviceProvider");
-
             this.cache = cache;
             ////this.trackedRepositories = trackedRepositories;
             this.repositoryHosts = repositoryHosts;

src/GitHub.App/ViewModels/RepositoryCloneViewModel.cs

@@ -134,7 +134,7 @@ IObservable<Unit> OnCloneRepository(object state)
                 // The following is a noop if the directory already exists.
                 operatingSystem.Directory.CreateDirectory(BaseRepositoryPath);
 
-                // Are we OK doing this here or should we be doing it after the clone succeeds.
+                // Are we OK doing this here or should we be doing it after the clone succeeds?
                 this.usageTracker.IncrementCloneCount();
 
                 return cloneService.CloneRepository(repository.CloneUrl, repository.Name, BaseRepositoryPath);