Merge pull request #15507 from CyrusNajmabadi/suggestionScrollBar

Update our code so that Suggestions show up in the scroll bar on the right. 

src/EditorFeatures/Core/Implementation/Diagnostics/DiagnosticsSuggestionTaggerProvider.cs

@@ -22,7 +22,8 @@ namespace Microsoft.CodeAnalysis.Editor.Implementation.Diagnostics
     [ContentType(ContentTypeNames.RoslynContentType)]
     [ContentType(ContentTypeNames.XamlContentType)]
     [TagType(typeof(SuggestionTag))]
-    internal partial class DiagnosticsSuggestionTaggerProvider : 
+    [TagType(typeof(IOverviewMarkTag))]
+    internal partial class DiagnosticsSuggestionTaggerProvider :
         AbstractDiagnosticsAdornmentTaggerProvider<SuggestionTag>
     {
         private static readonly IEnumerable<Option<bool>> s_tagSourceOptions =
@@ -69,7 +70,7 @@ protected internal override bool IncludeDiagnostic(DiagnosticData diagnostic)
 
         protected override SuggestionTag CreateTag(DiagnosticData diagnostic)
         {
-            lock(_suggestionTagGate)
+            lock (_suggestionTagGate)
             {
                 return _suggestionTag;
             }

src/EditorFeatures/Core/Implementation/Diagnostics/SuggestionTag.cs

@@ -7,6 +7,7 @@
 using Microsoft.CodeAnalysis.Editor.Implementation.Adornments;
 using Microsoft.VisualStudio.Text.Classification;
 using Microsoft.VisualStudio.Text.Editor;
+using Microsoft.VisualStudio.Text.Tagging;
 using Microsoft.VisualStudio.Utilities;
 
 namespace Microsoft.CodeAnalysis.Editor.Implementation.Diagnostics
@@ -20,8 +21,8 @@ internal sealed class SuggestionTagFormat : EditorFormatDefinition
 
         public SuggestionTagFormat()
         {
+            this.BackgroundColor = Color.FromArgb(200, 0xA5, 0xA5, 0xA5);
             this.ForegroundColor = Color.FromArgb(200, 0xA5, 0xA5, 0xA5);
-            this.BackgroundCustomizable = false;
             this.DisplayName = EditorFeaturesResources.Suggestion_ellipses;
         }
     }
@@ -29,10 +30,12 @@ public SuggestionTagFormat()
     /// <summary>
     /// Tag that specifies line separator.
     /// </summary>
-    internal class SuggestionTag : GraphicsTag
+    internal class SuggestionTag : GraphicsTag, IOverviewMarkTag
     {
         private Pen _graphicsTagPen;
 
+        public string MarkKindName => SuggestionTagFormat.ResourceName;
+
         public SuggestionTag(IEditorFormatMap editorFormatMap) 
             : base(editorFormatMap)
         {