Remove the synchrounous FindRefs codepaths for C# and VB.

The synchronous API still exists for TS to use until they
move over to the entirely async api.

src/EditorFeatures/CSharp/CSharpEditorFeatures.csproj

@@ -108,7 +108,6 @@
     <Compile Include="EventHookup\IHACK_EventHookupDismissalOnBufferChangePreventerService.cs" />
     <Compile Include="ExtractInterface\ExtractInterfaceCommandHandler.cs" />
     <Compile Include="ExtractMethod\ExtractMethodCommandHandler.cs" />
-    <Compile Include="FindReferences\CSharpFindReferencesService.cs" />
     <Compile Include="FindUsages\CSharpFindUsagesService.cs" />
     <Compile Include="Formatting\CSharpEditorFormattingService.cs" />
     <Compile Include="Formatting\Indentation\CSharpIndentationService.cs" />

src/EditorFeatures/CSharp/FindReferences/CSharpFindReferencesService.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.Collections.Generic;
-using System.Composition;
-using Microsoft.CodeAnalysis.Editor.FindReferences;
-using Microsoft.CodeAnalysis.Editor.Host;
-using Microsoft.CodeAnalysis.Host.Mef;
-
-namespace Microsoft.CodeAnalysis.Editor.CSharp.FindReferences
-{
-    [ExportLanguageService(typeof(IFindReferencesService), LanguageNames.CSharp), Shared]
-    internal class CSharpFindReferencesService : AbstractFindReferencesService
-    {
-        [ImportingConstructor]
-        public CSharpFindReferencesService(
-            [ImportMany] IEnumerable<IDefinitionsAndReferencesPresenter> referencedSymbolsPresenters,
-            [ImportMany] IEnumerable<INavigableItemsPresenter> navigableItemsPresenters)
-            : base(referencedSymbolsPresenters, navigableItemsPresenters)
-        {
-        }
-    }
-}
\ No newline at end of file

src/EditorFeatures/Core/EditorFeatures.csproj

@@ -398,7 +398,6 @@
     <Compile Include="Implementation\EndConstructGeneration\IEndConstructGenerationService.cs" />
     <Compile Include="Implementation\ExtractInterface\AbstractExtractInterfaceCommandHandler.cs" />
     <Compile Include="Implementation\ExtractMethod\AbstractExtractMethodCommandHandler.cs" />
-    <Compile Include="FindReferences\AbstractFindReferencesService.cs" />
     <Compile Include="FindReferences\FindReferencesCommandHandler.cs" />
     <Compile Include="FindReferences\IFindReferencesService.cs" />
     <Compile Include="Implementation\ForegroundNotification\ForegroundNotificationService.cs" />

src/EditorFeatures/Core/FindReferences/AbstractFindReferencesService.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.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.CodeAnalysis.Editor.FindUsages;
-using Microsoft.CodeAnalysis.Editor.Host;
-using Microsoft.CodeAnalysis.Editor.Shared.Utilities;
-using Microsoft.CodeAnalysis.FindSymbols;
-using Microsoft.CodeAnalysis.FindUsages;
-using Microsoft.CodeAnalysis.Navigation;
-using Microsoft.CodeAnalysis.Shared.Extensions;
-using Roslyn.Utilities;
-
-namespace Microsoft.CodeAnalysis.Editor.FindReferences
-{
-    internal abstract partial class AbstractFindReferencesService :
-        ForegroundThreadAffinitizedObject, IFindReferencesService
-    {
-        private readonly IEnumerable<IDefinitionsAndReferencesPresenter> _referenceSymbolPresenters;
-        private readonly IEnumerable<INavigableItemsPresenter> _navigableItemPresenters;
-
-        protected AbstractFindReferencesService(
-            IEnumerable<IDefinitionsAndReferencesPresenter> referenceSymbolPresenters,
-            IEnumerable<INavigableItemsPresenter> navigableItemPresenters)
-        {
-            _referenceSymbolPresenters = referenceSymbolPresenters;
-            _navigableItemPresenters = navigableItemPresenters;
-        }
-
-        private async Task<Tuple<IEnumerable<ReferencedSymbol>, Solution>> FindReferencedSymbolsAsync(
-            Document document, int position, IWaitContext waitContext)
-        {
-            var cancellationToken = waitContext.CancellationToken;
-
-            var symbolAndProject = await FindUsagesHelpers.GetRelevantSymbolAndProjectAtPositionAsync(
-                document, position, cancellationToken).ConfigureAwait(false);
-            if (symbolAndProject == null)
-            {
-                return null;
-            }
-
-            var symbol = symbolAndProject?.symbol;
-            var project = symbolAndProject?.project;
-
-            var displayName = FindUsagesHelpers.GetDisplayName(symbol);
-
-            waitContext.Message = string.Format(
-                EditorFeaturesResources.Finding_references_of_0, displayName);
-
-            var result = await SymbolFinder.FindReferencesAsync(symbol, project.Solution, cancellationToken).ConfigureAwait(false);
-
-            return Tuple.Create(result, project.Solution);
-        }
-
-        public bool TryFindReferences(Document document, int position, IWaitContext waitContext)
-        {
-            var cancellationToken = waitContext.CancellationToken;
-
-            var result = this.FindReferencedSymbolsAsync(document, position, waitContext).WaitAndGetResult(cancellationToken);
-            return TryDisplayReferences(result, cancellationToken);
-        }
-
-        private bool TryDisplayReferences(IEnumerable<INavigableItem> result)
-        {
-            if (result != null && result.Any())
-            {
-                var title = result.First().DisplayTaggedParts.JoinText();
-                foreach (var presenter in _navigableItemPresenters)
-                {
-                    presenter.DisplayResult(title, result);
-                    return true;
-                }
-            }
-
-            return false;
-        }
-
-        private bool TryDisplayReferences(
-            Tuple<IEnumerable<ReferencedSymbol>, Solution> result,
-            CancellationToken cancellationToken)
-        {
-            if (result != null && result.Item1 != null)
-            {
-                var solution = result.Item2;
-                var factory = solution.Workspace.Services.GetService<IDefinitionsAndReferencesFactory>();
-                var definitionsAndReferences = factory.CreateDefinitionsAndReferences(
-                    solution, result.Item1, includeHiddenLocations: false, cancellationToken: cancellationToken);
-
-                foreach (var presenter in _referenceSymbolPresenters)
-                {
-                    presenter.DisplayResult(definitionsAndReferences);
-                    return true;
-                }
-            }
-
-            return false;
-        }
-    }
-}
\ No newline at end of file

src/EditorFeatures/Core/FindReferences/FindReferencesCommandHandler.cs

@@ -74,15 +74,12 @@ public void ExecuteCommand(FindReferencesCommandArgs args, Action nextHandler)
         private bool TryExecuteCommand(int caretPosition, Document document)
         {
             var streamingService = document.GetLanguageService<IFindUsagesService>();
-            var synchronousService = document.GetLanguageService<IFindReferencesService>();
-
             var streamingPresenter = GetStreamingPresenter();
 
             // See if we're running on a host that can provide streaming results.
             // We'll both need a FAR service that can stream results to us, and 
             // a presenter that can accept streamed results.
-            var streamingEnabled = document.Project.Solution.Workspace.Options.GetOption(FeatureOnOffOptions.StreamingFindReferences, document.Project.Language);
-            if (streamingEnabled && streamingService != null && streamingPresenter != null)
+            if (streamingService != null && streamingPresenter != null)
             {
                 StreamingFindReferences(document, caretPosition, streamingService, streamingPresenter);
                 return true;
@@ -92,6 +89,7 @@ private bool TryExecuteCommand(int caretPosition, Document document)
             // or the host has no way to present results in a streaming manner.
             // Fall back to the old non-streaming approach to finding and presenting 
             // results.
+            var synchronousService = document.GetLanguageService<IFindReferencesService>();
             if (synchronousService != null)
             {
                 FindReferences(document, synchronousService, caretPosition);

src/EditorFeatures/Core/Shared/Options/FeatureOnOffOptions.cs

@@ -90,10 +90,6 @@ internal static class FeatureOnOffOptions
         public static readonly PerLanguageOption<bool> RefactoringVerification = new PerLanguageOption<bool>(
             nameof(FeatureOnOffOptions), nameof(RefactoringVerification), defaultValue: false);
 
-        [ExportOption]
-        public static readonly PerLanguageOption<bool> StreamingFindReferences = new PerLanguageOption<bool>(
-            nameof(FeatureOnOffOptions), nameof(StreamingFindReferences), defaultValue: true);
-
         [ExportOption]
         public static readonly PerLanguageOption<bool> StreamingGoToImplementation = new PerLanguageOption<bool>(
             nameof(FeatureOnOffOptions), nameof(StreamingGoToImplementation), defaultValue: true);

src/EditorFeatures/VisualBasic/BasicEditorFeatures.vbproj

@@ -91,7 +91,6 @@
     <Compile Include="EndConstructGeneration\VisualBasicEndConstructGenerationService.vb" />
     <Compile Include="ExtractInterface\ExtractInterfaceCommandHandler.vb" />
     <Compile Include="ExtractMethod\ExtractMethodCommandHandler.vb" />
-    <Compile Include="FindReferences\VisualBasicFindReferencesService.vb" />
     <Compile Include="FindUsages\VisualBasicFindUsagesService.vb" />
     <Compile Include="Formatting\Indentation\SmartTokenFormatter.vb" />
     <Compile Include="Formatting\Indentation\SmartTokenFormatterCommandHandler.vb" />

src/EditorFeatures/VisualBasic/FindReferences/VisualBasicFindReferencesService.vb

-' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
-
-Imports System.Composition
-Imports Microsoft.CodeAnalysis.Editor.FindReferences
-Imports Microsoft.CodeAnalysis.Editor.Host
-Imports Microsoft.CodeAnalysis.Host.Mef
-
-Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.FindReferences
-    <ExportLanguageService(GetType(IFindReferencesService), LanguageNames.VisualBasic), [Shared]>
-    Friend Class VisualBasicFindReferencesService
-        Inherits AbstractFindReferencesService
-
-        <ImportingConstructor>
-        Protected Sub New(<ImportMany> referencedSymbolsPresenters As IEnumerable(Of IDefinitionsAndReferencesPresenter),
-                          <ImportMany> navigableItemsPresenters As IEnumerable(Of INavigableItemsPresenter))
-            MyBase.New(referencedSymbolsPresenters, navigableItemsPresenters)
-        End Sub
-    End Class
-End Namespace
\ No newline at end of file