Update toggle block comment data interface with documentation.

src/EditorFeatures/CSharp/CommentSelection/CSharpToggleBlockCommentCommandHandler.cs

@@ -50,7 +50,7 @@ public CSharpToggleBlockCommentDocumentDataProvider(SyntaxNode root)
             /// <summary>
             /// Get a location of itself or the end of the token it is located in.
             /// </summary>
-            public int GetLocationAfterToken(int location)
+            public int GetEmptyCommentStartLocation(int location)
             {
                 var token = _root.FindToken(location);
                 if (token.Span.Contains(location))

src/EditorFeatures/Core/Implementation/CommentSelection/IToggleBlockCommentDocumentDataProvider.cs

@@ -7,7 +7,16 @@ namespace Microsoft.CodeAnalysis.Editor.Implementation.CommentSelection
 {
     interface IToggleBlockCommentDocumentDataProvider
     {
-        int GetLocationAfterToken(int location);
+        /// <summary>
+        /// Gets the location to insert an empty comment.
+        /// </summary>
+        /// <param name="location"></param>
+        /// <returns></returns>
+        int GetEmptyCommentStartLocation(int location);
+
+        /// <summary>
+        /// Gets all block comments in a particular document.
+        /// </summary>
         IEnumerable<TextSpan> GetBlockCommentsInDocument();
     }
 }

src/EditorFeatures/Core/Implementation/CommentSelection/ToggleBlockCommentCommandHandler.cs

@@ -165,7 +165,7 @@ public bool ExecuteCommand(CommentSelectionCommandArgs args, CommandExecutionCon
                 if (spanToAdd.IsEmpty)
                 {
                     // The location for the comment should be the caret or the location after the end of the token the caret is inside of.
-                    var locationAfterToken = blockCommentDataProvider.GetLocationAfterToken(spanToAdd.Start);
+                    var locationAfterToken = blockCommentDataProvider.GetEmptyCommentStartLocation(spanToAdd.Start);
                     spanToAdd = TextSpan.FromBounds(locationAfterToken, locationAfterToken);
                 }
 
@@ -415,7 +415,7 @@ public ToggleBlockCommentDocumentDataProvider(ITextSnapshot textSnapshot, Commen
                 _commentInfo = commentInfo;
             }
 
-            public int GetLocationAfterToken(int location)
+            public int GetEmptyCommentStartLocation(int location)
             {
                 return location;
             }