Cleanup code.

src/EditorFeatures/Core/FindReferences/FindReferencesCommandHandler.cs

@@ -126,7 +126,7 @@ private IStreamingFindUsagesPresenter GetStreamingPresenter()
                     // Let the presented know we're starging a search.  It will give us back
                     // the context object that the FAR service will push results into.
                     var context = presenter.StartSearch(
-                        EditorFeaturesResources.Find_References, canShowReferences: true);
+                        EditorFeaturesResources.Find_References, supportsReferences: true);
                     await findUsagesService.FindReferencesAsync(document, caretPosition, context).ConfigureAwait(false);
 
                     // Note: we don't need to put this in a finally.  The only time we might not hit

src/EditorFeatures/Core/Host/IStreamingFindReferencesPresenter.cs

@@ -21,7 +21,13 @@ internal interface IStreamingFindUsagesPresenter
         /// search completes <see cref="FindUsagesContext.OnCompletedAsync"/> should be called. 
         /// etc. etc.
         /// </summary>
-        FindUsagesContext StartSearch(string title, bool canShowReferences);
+        /// <param name="title">A title to display to the user in the presentation of the results.</param>
+        /// <param name="supportsReferences">Whether or not showing references is supported.
+        /// If true, then the presenter can group by definition, showing references underneath.
+        /// It can also show messages about no references being found at the end of the search.
+        /// If false, the presenter will not group by definitions, and will show the definition
+        /// items in isolation.</param>
+        FindUsagesContext StartSearch(string title, bool supportsReferences);
     }
 
     internal static class IStreamingFindUsagesPresenterExtensions
@@ -65,8 +71,7 @@ internal static class IStreamingFindUsagesPresenterExtensions
             {
                 // We have multiple definitions, or we have definitions with multiple locations.
                 // Present this to the user so they can decide where they want to go to.
-
-                var context = presenter.StartSearch(title, canShowReferences: false);
+                var context = presenter.StartSearch(title, supportsReferences: false);
                 foreach (var definition in nonExternalItems)
                 {
                     await context.OnDefinitionFoundAsync(definition).ConfigureAwait(false);

src/VisualStudio/Core/Next/FindReferences/Contexts/WithReferencesFindUsagesContext.cs

@@ -14,6 +14,11 @@
 
 namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
+    /// <summary>
+    /// Context to be used for FindAllReferences (as opposed to FindImplementations/GoToDef).
+    /// This context supports showing reference items, and will display appropriate messages
+    /// about no-references being found for a definition at the end of the search.
+    /// </summary>
     internal class WithReferencesFindUsagesContext : AbstractTableDataSourceFindUsagesContext
     {
         public WithReferencesFindUsagesContext(

src/VisualStudio/Core/Next/FindReferences/Contexts/WithoutReferencesFindUsagesContext.cs

@@ -9,6 +9,11 @@
 
 namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
+    /// <summary>
+    /// Context to be used for FindImplementations/GoToDef (as opposed to FindReferences).
+    /// This context will not group entries by definition, and will instead just create
+    /// entries for the definitions themselves.
+    /// </summary>
     internal class WithoutReferencesFindUsagesContext : AbstractTableDataSourceFindUsagesContext
     {
         public WithoutReferencesFindUsagesContext(
@@ -18,9 +23,11 @@ internal class WithoutReferencesFindUsagesContext : AbstractTableDataSourceFindU
         {
         }
 
+        // We should never be called in a context where we get references.
         protected override Task OnReferenceFoundWorkerAsync(SourceReferenceItem reference)
             => throw new InvalidOperationException();
 
+        // Nothing to do on completion.
         protected override Task OnCompletedAsyncWorkerAsync()
             => SpecializedTasks.EmptyTask;
 

src/VisualStudio/Core/Next/FindReferences/Entries/AbstractDocumentSpanEntry.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.Generic;
+using System.Windows;
+using System.Windows.Documents;
 using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;
+using Microsoft.VisualStudio.Shell.TableControl;
 using Microsoft.VisualStudio.Shell.TableManager;
 
 namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
+    /// <summary>
+    /// Base type of all <see cref="Entry"/>s that represent some source location in 
+    /// a <see cref="Document"/>.  Navigation to that location is provided by this type.
+    /// Subclasses can be used to provide customized line text to display in the entry.
+    /// </summary>
     internal abstract class AbstractDocumentSpanEntry : Entry
     {
         private readonly AbstractTableDataSourceFindUsagesContext _context;
@@ -55,5 +65,22 @@ protected override object GetValueWorker(string keyName)
 
             return null;
         }
+
+        public sealed override bool TryCreateColumnContent(string columnName, out FrameworkElement content)
+        {
+            if (columnName == StandardTableColumnDefinitions2.LineText)
+            {
+                var inlines = CreateLineTextInlines();
+                var textBlock = inlines.ToTextBlock(Presenter.TypeMap, wrap: false);
+
+                content = textBlock;
+                return true;
+            }
+
+            content = null;
+            return false;
+        }
+
+        protected abstract IList<Inline> CreateLineTextInlines();
     }
 }
\ No newline at end of file

src/VisualStudio/Core/Next/FindReferences/Entries/DefinitionItemEntry.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.Windows;
+using System.Collections.Generic;
+using System.Windows.Documents;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Editor.Shared.Extensions;
 using Microsoft.CodeAnalysis.Text;
-using Microsoft.VisualStudio.Shell.TableControl;
 
 namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
+    /// <summary>
+    /// Shows a DefinitionItem as a Row in the FindReferencesWindow.  Only used for
+    /// GoToDefinition/FindImplementations.  In these operations, we don't want to 
+    /// create a DefinitionBucket.  So we instead just so the symbol as a normal row.
+    /// </summary>
     internal class DefinitionItemEntry : AbstractDocumentSpanEntry
     {
         public DefinitionItemEntry(
@@ -21,19 +26,7 @@ internal class DefinitionItemEntry : AbstractDocumentSpanEntry
         {
         }
 
-            public override bool TryCreateColumnContent(string columnName, out FrameworkElement content)
-            {
-                if (columnName == StandardTableColumnDefinitions2.LineText)
-                {
-                    var inlines = DefinitionBucket.DefinitionItem.DisplayParts.ToInlines(Presenter.TypeMap);
-                    var textBlock = inlines.ToTextBlock(Presenter.TypeMap, wrap: false);
-
-                    content = textBlock;
-                    return true;
-                }
-
-                content = null;
-                return false;
-            }
+        protected override IList<Inline> CreateLineTextInlines()
+            => DefinitionBucket.DefinitionItem.DisplayParts.ToInlines(Presenter.TypeMap);
     }
 }
\ No newline at end of file

src/VisualStudio/Core/Next/FindReferences/Entries/DocumentSpanEntry.cs

@@ -25,7 +25,7 @@ namespace Microsoft.VisualStudio.LanguageServices.FindUsages
     internal class DocumentSpanEntry : AbstractDocumentSpanEntry
     {
         private readonly bool _isDefinitionLocation;
-        private readonly ClassifiedSpansAndHighlightSpan _classifiedSpans;
+        private readonly ClassifiedSpansAndHighlightSpan _classifiedSpansAndHighlights;
 
         public DocumentSpanEntry(
             AbstractTableDataSourceFindUsagesContext context,
@@ -38,52 +38,31 @@ internal class DocumentSpanEntry : AbstractDocumentSpanEntry
             : base(context, definitionBucket, documentSpan, projectGuid, sourceText)
         {
             _isDefinitionLocation = isDefinitionLocation;
-            _classifiedSpans = classifiedSpans;
+            _classifiedSpansAndHighlights = classifiedSpans;
         }
 
-        public override bool TryCreateColumnContent(string columnName, out FrameworkElement content)
+        protected override IList<System.Windows.Documents.Inline> CreateLineTextInlines()
         { 
-            if (columnName == StandardTableColumnDefinitions2.LineText)
-            {
-                var inlines = GetHighlightedInlines(Presenter, _sourceText, _classifiedSpans, _isDefinitionLocation);
-                var textBlock = inlines.ToTextBlock(Presenter.TypeMap, wrap: false);
-
-                LazyToolTip.AttachTo(textBlock, CreateDisposableToolTip);
-
-                content = textBlock;
-                return true;
-            }
-
-            content = null;
-            return false;
-        }
-
-        private static IList<System.Windows.Documents.Inline> GetHighlightedInlines(
-            StreamingFindUsagesPresenter presenter,
-            SourceText sourceText,
-            ClassifiedSpansAndHighlightSpan classifiedSpansAndHighlight,
-            bool isDefinition)
-        {
-            var propertyId = isDefinition
+            var propertyId = _isDefinitionLocation
                 ? DefinitionHighlightTag.TagId
                 : ReferenceHighlightTag.TagId;
 
-            var properties = presenter.FormatMapService
+            var properties = Presenter.FormatMapService
                                       .GetEditorFormatMap("text")
                                       .GetProperties(propertyId);
             var highlightBrush = properties["Background"] as Brush;
 
-            var classifiedSpans = classifiedSpansAndHighlight.ClassifiedSpans;
+            var classifiedSpans = _classifiedSpansAndHighlights.ClassifiedSpans;
             var classifiedTexts = classifiedSpans.SelectAsArray(
-                cs => new ClassifiedText(cs.ClassificationType, sourceText.ToString(cs.TextSpan)));
+                cs => new ClassifiedText(cs.ClassificationType, _sourceText.ToString(cs.TextSpan)));
 
             var inlines = classifiedTexts.ToInlines(
-                presenter.TypeMap,
+                Presenter.TypeMap,
                 runCallback: (run, classifiedText, position) =>
                 {
                     if (highlightBrush != null)
                     {
-                        if (position == classifiedSpansAndHighlight.HighlightSpan.Start)
+                        if (position == _classifiedSpansAndHighlights.HighlightSpan.Start)
                         {
                             run.SetValue(
                                 System.Windows.Documents.TextElement.BackgroundProperty,

src/VisualStudio/Core/Next/FindReferences/StreamingFindUsagesPresenter.cs

@@ -28,16 +28,16 @@ internal partial class StreamingFindUsagesPresenter :
 
         private readonly IServiceProvider _serviceProvider;
 
-        private readonly IFindAllReferencesService _vsFindAllReferencesService;
-        private readonly VisualStudioWorkspace _workspace;
-
         public readonly ITextBufferFactoryService TextBufferFactoryService;
         public readonly IProjectionBufferFactoryService ProjectionBufferFactoryService;
         public readonly IEditorOptionsFactoryService EditorOptionsFactoryService;
         public readonly ITextEditorFactoryService TextEditorFactoryService;
         public readonly IContentTypeRegistryService ContentTypeRegistryService;
-        public readonly IEditorFormatMapService FormatMapService;
         public readonly ClassificationTypeMap TypeMap;
+        public readonly IEditorFormatMapService FormatMapService;
+
+        private readonly IFindAllReferencesService _vsFindAllReferencesService;
+        private readonly VisualStudioWorkspace _workspace;
 
         [ImportingConstructor]
         public StreamingFindUsagesPresenter(