Fix handing of batch adding/removal of documents

Two bugs being fixed here:

1. When we remove a document in a non-batch scenario, we close any
   information related to the open document. If we were in a batch
   scenario, the SetCurrentSolution we do to apply the new Solution
   snapshot didn't go through that. Now we do.
2. UpdateSolutionForBatch wasn't calling the delegates given; this would
   have meant that additional files being added in a batch would have
   been added a regular source files.

src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioProject.cs

@@ -298,8 +298,37 @@ private void OnBatchScopeDisposed()
 
                 _workspace.ApplyBatchChangeToProject(Id, solution =>
                 {
-                    solution = _sourceFiles.UpdateSolutionForBatch(solution, documentFileNamesAdded, documentsToOpen, (s, d) => s.AddDocument(d), (s, id) => s.RemoveDocument(id));
-                    solution = _additionalFiles.UpdateSolutionForBatch(solution, documentFileNamesAdded, documentsToOpen, (s, d) => s.AddAdditionalDocument(d), (s, id) => s.RemoveAdditionalDocument(id));
+                    solution = _sourceFiles.UpdateSolutionForBatch(
+                        solution,
+                        documentFileNamesAdded,
+                        documentsToOpen,
+                        (s, documents) => solution.AddDocuments(documents),
+                        (s, id) =>
+                        {
+                            // Clear any document-specific data now (like open file trackers, etc.)
+                            _workspace.ClearDocumentData(id);
+                            return s.RemoveDocument(id);
+                        });
+
+                    solution = _additionalFiles.UpdateSolutionForBatch(
+                        solution,
+                        documentFileNamesAdded,
+                        documentsToOpen,
+                        (s, documents) =>
+                        {
+                            foreach (var document in documents)
+                            {
+                                s = s.AddAdditionalDocument(document);
+                            }
+
+                            return s;
+                        },
+                        (s, id) =>
+                        {
+                            // Clear any document-specific data now (like open file trackers, etc.)
+                            _workspace.ClearDocumentData(id);
+                            return s.RemoveAdditionalDocument(id);
+                        });
 
                     // Metadata reference adding...
                     if (_metadataReferencesAddedInBatch.Count > 0)
@@ -1083,11 +1112,11 @@ public void ProcessFileChange(string fullFilePath)
                 Solution solution,
                 ImmutableArray<string>.Builder documentFileNamesAdded,
                 List<(DocumentId, SourceTextContainer)> documentsToOpen,
-                Func<Solution, DocumentInfo, Solution> addDocument,
+                Func<Solution, ImmutableArray<DocumentInfo>, Solution> addDocuments,
                 Func<Solution, DocumentId, Solution> removeDocument)
             {
                 // Document adding...
-                solution = solution.AddDocuments(_documentsAddedInBatch.ToImmutable());
+                solution = addDocuments(solution, _documentsAddedInBatch.ToImmutable());
 
                 foreach (var documentInfo in _documentsAddedInBatch)
                 {
@@ -1104,7 +1133,7 @@ public void ProcessFileChange(string fullFilePath)
                 // Document removing...
                 foreach (var documentId in _documentsRemovedInBatch)
                 {
-                    solution = solution.RemoveDocument(documentId);
+                    solution = removeDocument(solution, documentId);
                 }
 
                 ClearAndZeroCapacity(_documentsRemovedInBatch);

src/Workspaces/Core/Portable/Workspace/Workspace.cs

@@ -282,7 +282,7 @@ protected virtual void ClearProjectData(ProjectId projectId)
         /// Override this method if you want to do additional work when a document is removed.
         /// Call the base method at the end of your method.
         /// </summary>
-        protected virtual void ClearDocumentData(DocumentId documentId)
+        protected internal virtual void ClearDocumentData(DocumentId documentId)
         {
             this.ClearOpenDocument(documentId);
         }