Add back original method signatures as extensions (for convenience)...

src/VisualStudio/Next/Diagnostics/OutOfProcDiagnosticAnalyzerExecutor.cs

@@ -17,6 +17,7 @@
 using Microsoft.CodeAnalysis.Remote;
 using Microsoft.CodeAnalysis.Remote.Diagnostics;
 using Microsoft.CodeAnalysis.Workspaces.Diagnostics;
+using Microsoft.VisualStudio.LanguageServices.Implementation.Extensions;
 using Microsoft.VisualStudio.LanguageServices.Remote;
 using Roslyn.Utilities;
 
@@ -84,7 +85,7 @@ internal class OutOfProcDiagnosticAnalyzerExecutor : IRemoteHostDiagnosticAnalyz
             }
 
             // TODO: send telemetry on session
-            using (var session = await client.CreateServiceSessionAsync(WellKnownServiceHubServices.CodeAnalysisService, solution, cancellationToken).ConfigureAwait(false))
+            using (var session = await client.CreateCodeAnalysisServiceSessionAsync(solution, cancellationToken).ConfigureAwait(false))
             {
                 var argument = new DiagnosticArguments(
                     analyzerDriver.AnalysisOptions.ReportSuppressedDiagnostics,

src/VisualStudio/Next/Extensions/RemoteHostClientExtensions.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Remote;
+using Microsoft.VisualStudio.LanguageServices.Remote;
+using static Microsoft.VisualStudio.LanguageServices.Remote.RemoteHostClient;
+
+namespace Microsoft.VisualStudio.LanguageServices.Implementation.Extensions
+{
+    internal static class RemoteHostClientExtensions
+    {
+        public static Task<Session> CreateCodeAnalysisServiceSessionAsync(this RemoteHostClient client, Solution solution, CancellationToken cancellationToken)
+        {
+            return CreateCodeAnalysisServiceSessionAsync(client, solution, callbackTarget: null, cancellationToken: cancellationToken);
+        }
+
+        public static Task<Session> CreateCodeAnalysisServiceSessionAsync(this RemoteHostClient client, Solution solution, object callbackTarget, CancellationToken cancellationToken)
+        {
+            return client.CreateServiceSessionAsync(WellKnownServiceHubServices.CodeAnalysisService, solution, callbackTarget, cancellationToken);
+        }
+    }
+}

src/VisualStudio/Next/ServicesVisualStudio.Next.csproj

@@ -93,6 +93,7 @@
       <Link>Shared\WellKnownServiceHubServices.cs</Link>
     </Compile>
     <Compile Include="Diagnostics\OutOfProcDiagnosticAnalyzerExecutor.cs" />
+    <Compile Include="Extensions\RemoteHostClientExtensions.cs" />
     <Compile Include="FindReferences\FindReferencesTableControlEventProcessorProvider.cs" />
     <Compile Include="FindReferences\ISupportsNavigation.cs" />
     <Compile Include="FindReferences\StreamingFindReferencesPresenter.cs" />
@@ -125,4 +126,4 @@
     <InternalsVisibleTo Include="Microsoft.CodeAnalysis.TestImpact.BuildManager" />
   </ItemGroup>
   <Import Project="..\..\..\build\Targets\VSL.Imports.targets" />
-</Project>
+</Project>
\ No newline at end of file