Initialize menus on Main thread

Avoid using SwitchToMainThreadAsync because it can hang when called before a solution is loaded.

Author: jcansdale

src/GitHub.InlineReviews/InlineReviewsPackage.cs

@@ -13,7 +13,8 @@
 
 namespace GitHub.InlineReviews
 {
-    [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = true)]
+    // Initialize menus on Main thread.
+    [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = false)]
     [Guid(Guids.InlineReviewsPackageId)]
     [ProvideAutoLoad(UIContextGuids80.SolutionExists)]
     [ProvideMenuResource("Menus.ctmenu", 1)]
@@ -24,12 +25,10 @@ protected override async Task InitializeAsync(
             CancellationToken cancellationToken,
             IProgress<ServiceProgressData> progress)
         {
-            await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
-
             var menuService = (IMenuCommandService)(await GetServiceAsync(typeof(IMenuCommandService)));
             var componentModel = (IComponentModel)(await GetServiceAsync(typeof(SComponentModel)));
-            var exports = componentModel.DefaultExportProvider;
 
+            var exports = componentModel.DefaultExportProvider;
             menuService.AddCommands(
                 exports.GetExportedValue<INextInlineCommentCommand>(),
                 exports.GetExportedValue<IPreviousInlineCommentCommand>());

src/GitHub.VisualStudio/GitHubPackage.cs

@@ -24,12 +24,13 @@
 
 namespace GitHub.VisualStudio
 {
-    [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = true)]
+    // Initialize menus on Main thread.
+    [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = false)]
     [InstalledProductRegistration("#110", "#112", AssemblyVersionInformation.Version, IconResourceID = 400)]
     [Guid(Guids.guidGitHubPkgString)]
     [ProvideMenuResource("Menus.ctmenu", 1)]
     // Only initialize when we're in the context of a Git repository.
-    [ProvideAutoLoad(Guids.UIContext_Git, PackageAutoLoadFlags.BackgroundLoad)]
+    [ProvideAutoLoad(Guids.UIContext_Git)]
     [ProvideToolWindow(typeof(GitHubPane), Orientation = ToolWindowOrientation.Right, Style = VsDockStyle.Tabbed, Window = EnvDTE.Constants.vsWindowKindSolutionExplorer)]
     [ProvideOptionPage(typeof(OptionsPage), "GitHub for Visual Studio", "General", 0, 0, supportsAutomation: true)]
     public class GitHubPackage : AsyncPackage
@@ -71,9 +72,6 @@ async Task InitializeMenus()
             var menuService = (IMenuCommandService)(await GetServiceAsync(typeof(IMenuCommandService)));
             var componentModel = (IComponentModel)(await GetServiceAsync(typeof(SComponentModel)));
 
-            // IMenuCommandService.AddCommand uses IServiceProvider.GetService and must be called on Main thread.
-            await ThreadingHelper.SwitchToMainThreadAsync();
-
             var exports = componentModel.DefaultExportProvider;
             menuService.AddCommands(
                 exports.GetExportedValue<IAddConnectionCommand>(),