Remove unused functionality.

src/Workspaces/CSharp/Portable/EmbeddedLanguages/LanguageServices/CSharpEmbeddedLanguagesProvider.cs

@@ -21,17 +21,5 @@ public CSharpEmbeddedLanguagesProvider()
                    CSharpVirtualCharService.Instance)
         {
         }
-
-        internal override void AddComment(SyntaxEditor editor, SyntaxToken stringLiteral, string commentContents)
-        {
-            var triviaList = SyntaxFactory.TriviaList(
-                SyntaxFactory.Comment($"/*{commentContents}*/"),
-                SyntaxFactory.ElasticSpace);
-
-            var newStringLiteral = stringLiteral.WithLeadingTrivia(
-                stringLiteral.LeadingTrivia.AddRange(triviaList));
-
-            editor.ReplaceNode(stringLiteral.Parent, stringLiteral.Parent.ReplaceToken(stringLiteral, newStringLiteral));
-        }
     }
 }

src/Workspaces/Core/Portable/EmbeddedLanguages/LanguageServices/AbstractEmbeddedLanguagesProvider.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;
 using System.Collections.Immutable;
-using System.Threading;
-using Microsoft.CodeAnalysis.Editing;
 using Microsoft.CodeAnalysis.EmbeddedLanguages.RegularExpressions.LanguageServices;
 using Microsoft.CodeAnalysis.EmbeddedLanguages.VirtualChars;
 using Microsoft.CodeAnalysis.LanguageServices;
@@ -31,13 +28,5 @@ internal abstract class AbstractEmbeddedLanguagesProvider : IEmbeddedLanguagesPr
 
         public ImmutableArray<IEmbeddedLanguage> GetEmbeddedLanguages()
             => _embeddedLanguages;
-
-        /// <summary>
-        /// Helper method used by the VB and C# <see cref="IEmbeddedCodeFixProvider"/>s so they can
-        /// add special comments to string literals to convey that language services should light up
-        /// for them.
-        /// </summary>
-        internal abstract void AddComment(
-            SyntaxEditor editor, SyntaxToken stringLiteral, string commentContents);
     }
 }

src/Workspaces/VisualBasic/Portable/EmbeddedLanguages/LanguageServices/VisualBasicEmbeddedLanguagesProvider.vb

@@ -21,20 +21,5 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.EmbeddedLanguages.LanguageServices
                        VisualBasicSemanticFactsService.Instance,
                        VisualBasicVirtualCharService.Instance)
         End Sub
-
-        Friend Overrides Sub AddComment(editor As SyntaxEditor, stringLiteral As SyntaxToken, commentContents As String)
-            Dim trivia = SyntaxFactory.TriviaList(
-                SyntaxFactory.CommentTrivia($"' {commentContents}"),
-                SyntaxFactory.ElasticCarriageReturnLineFeed)
-
-            Dim containingStatement = stringLiteral.Parent.GetAncestor(Of StatementSyntax)
-
-            Dim leadingBlankLines = containingStatement.GetLeadingBlankLines()
-
-            Dim newStatement = containingStatement.GetNodeWithoutLeadingBlankLines().
-                                                   WithPrependedLeadingTrivia(leadingBlankLines.AddRange(trivia))
-
-            editor.ReplaceNode(containingStatement, newStatement)
-        End Sub
     End Class
 End Namespace