Remove unused method from sighelp

src/EditorFeatures/Core/Implementation/IntelliSense/IDocumentProvider.cs

@@ -10,8 +10,7 @@ namespace Microsoft.CodeAnalysis.Editor.Implementation.IntelliSense
 {
     internal interface IDocumentProvider
     {
-        Task<Document> GetDocumentAsync(ITextSnapshot snapshot, CancellationToken cancellationToken);
-        Document GetOpenDocumentInCurrentContextWithChanges(ITextSnapshot snapshot);
+        Document GetDocument(ITextSnapshot snapshot, CancellationToken cancellationToken);
     }
 
     internal class DocumentProvider : ForegroundThreadAffinitizedObject, IDocumentProvider
@@ -21,16 +20,10 @@ public DocumentProvider(IThreadingContext threadingContext)
         {
         }
 
-        public Task<Document> GetDocumentAsync(ITextSnapshot snapshot, CancellationToken cancellationToken)
+        public Document GetDocument(ITextSnapshot snapshot, CancellationToken cancellationToken)
         {
             AssertIsBackground();
-            return Task.FromResult(snapshot.AsText().GetDocumentWithFrozenPartialSemantics(cancellationToken));
-        }
-
-        public Document GetOpenDocumentInCurrentContextWithChanges(ITextSnapshot snapshot)
-        {
-            var text = snapshot.AsText();
-            return text.GetOpenDocumentInCurrentContextWithChanges();
+            return snapshot.AsText().GetDocumentWithFrozenPartialSemantics(cancellationToken);
         }
     }
 }

src/EditorFeatures/Core/Implementation/IntelliSense/SignatureHelp/Controller.Session_ComputeModel.cs

@@ -55,7 +55,7 @@ internal partial class Session
                         AssertIsBackground();
                         cancellationToken.ThrowIfCancellationRequested();
 
-                        var document = await Controller.DocumentProvider.GetDocumentAsync(caretPosition.Snapshot, cancellationToken).ConfigureAwait(false);
+                        var document = Controller.DocumentProvider.GetDocument(caretPosition.Snapshot, cancellationToken);
                         if (document == null)
                         {
                             return currentModel;

src/EditorFeatures/Test2/IntelliSense/SignatureHelpControllerTests.vb

@@ -25,7 +25,7 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
         <WpfFact>
         Public Sub InvokeSignatureHelpWithoutDocumentShouldNotStartNewSession()
             Dim emptyProvider = New Mock(Of IDocumentProvider)
-            emptyProvider.Setup(Function(p) p.GetDocumentAsync(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken))).Returns(Task.FromResult(DirectCast(Nothing, Document)))
+            emptyProvider.Setup(Function(p) p.GetDocument(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken))).Returns(DirectCast(Nothing, Document))
             Dim controller As Controller = CreateController(documentProvider:=emptyProvider)
             controller.WaitForController()
 
@@ -217,7 +217,7 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
                 New TypeCharCommandArgs(CreateMock(Of ITextView), CreateMock(Of ITextBuffer), "a"c),
                 Sub() GetMocks(controller).Buffer.Insert(0, "a"), TestCommandExecutionContext.Create())
 
-            GetMocks(controller).DocumentProvider.Verify(Function(p) p.GetDocumentAsync(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken)), Times.Never)
+            GetMocks(controller).DocumentProvider.Verify(Function(p) p.GetDocument(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken)), Times.Never)
         End Sub
 
         Private Shared ReadOnly s_controllerMocksMap As New ConditionalWeakTable(Of Controller, ControllerMocks)
@@ -251,8 +251,7 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
             Dim asyncListener = New Mock(Of IAsynchronousOperationListener)
             If documentProvider Is Nothing Then
                 documentProvider = New Mock(Of IDocumentProvider)
-                documentProvider.Setup(Function(p) p.GetDocumentAsync(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken))).Returns(Task.FromResult(document))
-                documentProvider.Setup(Function(p) p.GetOpenDocumentInCurrentContextWithChanges(It.IsAny(Of ITextSnapshot))).Returns(document)
+                documentProvider.Setup(Function(p) p.GetDocument(It.IsAny(Of ITextSnapshot), It.IsAny(Of CancellationToken))).Returns(document)
             End If
 
             If provider Is Nothing Then