Remove unused file.

src/VisualStudio/Core/Def/Implementation/Library/FindResults/TreeItems/AbstractTreeItem.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 Microsoft.CodeAnalysis;
 
 namespace Microsoft.VisualStudio.LanguageServices.Implementation.Library.FindResults
 {

src/VisualStudio/Core/Def/Implementation/Library/FindResults/TreeItems/ExternalLanguageDefinitionTreeItem.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.
-
-#if false
-using System;
-using System.Runtime.InteropServices;
-using Microsoft.VisualStudio.LanguageServices.Implementation.ProjectSystem;
-using Microsoft.VisualStudio.Shell.Interop;
-using Microsoft.VisualStudio.TextManager.Interop;
-using OLEServiceProvider = Microsoft.VisualStudio.OLE.Interop.IServiceProvider;
-
-namespace Microsoft.VisualStudio.LanguageServices.Implementation.Library.FindResults
-{
-    internal class ExternalLanguageDefinitionTreeItem : AbstractTreeItem
-    {
-        private readonly IServiceProvider _serviceProvider;
-        private readonly string _filePath;
-        private readonly int _lineNumber;
-        private readonly int _charOffset;
-
-        /// <summary>
-        /// A definition from an external language service (e.g. xaml).
-        /// </summary>
-        public ExternalLanguageDefinitionTreeItem(string filePath, int lineNumber, int offset, string symbolName, ushort glyphIndex, IServiceProvider serviceProvider)
-            : base(glyphIndex)
-        {
-            _filePath = filePath;
-            _lineNumber = lineNumber;
-            _charOffset = offset;
-            _serviceProvider = serviceProvider;
-
-            SetDisplayProperties(
-                filePath,
-                lineNumber,
-                offset,
-                offset,
-                GetSourceLine(filePath, lineNumber, serviceProvider),
-                symbolName.Length,
-                projectNameDisambiguator: string.Empty);
-        }
-
-        private static string GetSourceLine(string filePath, int lineNumber, IServiceProvider serviceProvider)
-        {
-            using (var invisibleEditor = new InvisibleEditor(serviceProvider, filePath, needsSave: false, needsUndoDisabled: false))
-            {
-                var vsTextLines = invisibleEditor.VsTextLines;
-                int lineLength;
-                string lineText;
-
-                if (vsTextLines != null &&
-                    vsTextLines.GetLengthOfLine(lineNumber, out lineLength) == VSConstants.S_OK &&
-                    vsTextLines.GetLineText(lineNumber, 0, lineNumber, lineLength, out lineText) == VSConstants.S_OK)
-                {
-                    return lineText;
-                }
-
-                return ServicesVSResources.Preview_unavailable;
-            }
-        }
-
-        public override bool CanGoToDefinition()
-        {
-            return true;
-        }
-
-        public override int GoToSource()
-        {
-            return (TryOpenFile() && TryNavigateToPosition()) ? VSConstants.S_OK : VSConstants.E_FAIL;
-        }
-
-        private bool TryOpenFile()
-        {
-            var shellOpenDocument = (IVsUIShellOpenDocument)_serviceProvider.GetService(typeof(SVsUIShellOpenDocument));
-            var textViewGuid = VSConstants.LOGVIEWID.TextView_guid;
-
-            uint itemid;
-            IVsUIHierarchy hierarchy;
-            OLEServiceProvider oleServiceProvider;
-            IVsWindowFrame frame;
-            if (shellOpenDocument.OpenDocumentViaProject(_filePath, ref textViewGuid, out oleServiceProvider, out hierarchy, out itemid, out frame) == VSConstants.S_OK)
-            {
-                frame.Show();
-                return true;
-            }
-
-            return false;
-        }
-
-        private bool TryNavigateToPosition()
-        {
-            IVsRunningDocumentTable docTable = (IVsRunningDocumentTable)_serviceProvider.GetService(typeof(SVsRunningDocumentTable));
-
-            IntPtr bufferPtr;
-            IVsHierarchy hierarchy;
-            uint cookie;
-            uint itemid;
-
-            if (docTable.FindAndLockDocument((uint)_VSRDTFLAGS.RDT_NoLock, _filePath, out hierarchy, out itemid, out bufferPtr, out cookie) != VSConstants.S_OK)
-            {
-                return false;
-            }
-
-            try
-            {
-                var lines = Marshal.GetObjectForIUnknown(bufferPtr) as IVsTextLines;
-                if (lines == null)
-                {
-                    return false;
-                }
-
-                var textManager = (IVsTextManager)_serviceProvider.GetService(typeof(SVsTextManager));
-                if (textManager == null)
-                {
-                    return false;
-                }
-
-                return textManager.NavigateToLineAndColumn(
-                    lines, VSConstants.LOGVIEWID.TextView_guid, _lineNumber, _charOffset, _lineNumber, _charOffset) == VSConstants.S_OK;
-            }
-            finally
-            {
-                if (bufferPtr != IntPtr.Zero)
-                {
-                    Marshal.Release(bufferPtr);
-                }
-            }
-        }
-    }
-}
-#endif
\ No newline at end of file

src/VisualStudio/Core/Def/ServicesVisualStudio.csproj

@@ -454,7 +454,6 @@
     <Compile Include="Implementation\Library\AbstractLibraryManager_IVsSimpleLibrary2.cs" />
     <Compile Include="Implementation\Library\AbstractObjectList.cs" />
     <Compile Include="Implementation\Library\FindResults\TreeItems\AbstractTreeItem.cs" />
-    <Compile Include="Implementation\Library\FindResults\TreeItems\ExternalLanguageDefinitionTreeItem.cs" />
     <Compile Include="Implementation\Library\FindResults\LibraryManager.cs" />
     <Compile Include="Implementation\Library\FindResults\LibraryManager_FindReferences.cs" />
     <Compile Include="Implementation\Library\FindResults\LibraryManager_GoToDefinition.cs" />