Simplify approach

src/VisualStudio/Core/Def/Implementation/TodoComments/VisualStudioTodoCommentsService.cs

@@ -195,18 +195,6 @@ public ImmutableArray<TodoCommentData> GetTodoItems(Workspace workspace, Documen
             return SpecializedCollections.EmptyEnumerable<UpdatedEventArgs>();
         }
 
-        /// <summary>
-        /// Callback from the OOP service back into us.
-        /// </summary>
-        public async Task OnDocumentRemovedAsync(DocumentId documentId, CancellationToken cancellationToken)
-        {
-            var workQueue = await _workQueueSource.Task.ConfigureAwait(false);
-
-            // treat this as if we have no todo comments for this file. ProcessTodoCommentInfosAsync
-            // will handle actually clearing out the data.
-            workQueue.AddWork(new DocumentAndComments(documentId, ImmutableArray<TodoCommentData>.Empty));
-        }
-
         /// <summary>
         /// Callback from the OOP service back into us.
         /// </summary>

src/Workspaces/Core/Portable/TodoComments/ITodoCommentsListener.cs

@@ -11,12 +11,10 @@
 namespace Microsoft.CodeAnalysis.TodoComments
 {
     /// <summary>
-    /// Callback the host (VS) passes to the OOP service to allow it to send batch notifications
-    /// about todo comments.
+    /// Callback the host (VS) passes to the OOP service to allow it to send batch notifications about todo comments.
     /// </summary>
     internal interface ITodoCommentsListener
     {
-        Task OnDocumentRemovedAsync(DocumentId documentId, CancellationToken cancellationToken);
         Task ReportTodoCommentDataAsync(DocumentId documentId, ImmutableArray<TodoCommentData> data, CancellationToken cancellationToken);
     }
 }

src/Workspaces/Remote/ServiceHub/Services/TodoComments/RemoteTodoCommentsIncrementalAnalyzer.cs

@@ -4,6 +4,7 @@
 
 #nullable enable
 
+using System;
 using System.Collections.Immutable;
 using System.Threading;
 using System.Threading.Tasks;
@@ -38,9 +39,10 @@ public override bool NeedsReanalysisOnOptionChanged(object sender, OptionChanged
 
         public override Task RemoveDocumentAsync(DocumentId documentId, CancellationToken cancellationToken)
         {
+            // Just report this back as there being no more comments for this document.
             return _endPoint.InvokeAsync(
-                nameof(ITodoCommentsListener.OnDocumentRemovedAsync),
-                new object[] { documentId },
+                nameof(ITodoCommentsListener.ReportTodoCommentDataAsync),
+                new object[] { documentId, Array.Empty<TodoCommentData>() },
                 cancellationToken);
         }