Remove the remaining unnecessary awaits from analysis_server

Change-Id: I3d10c244ca711a0978cb2d4a99dbe1f3bedc159c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/144863
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/lib/src/analysis_server.dart

@@ -597,8 +597,6 @@ class AnalysisServer extends AbstractAnalysisServer {
   }
 
   Future<void> _scheduleAnalysisImplementedNotification() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var files = analysisServices[AnalysisService.IMPLEMENTED];
     if (files != null) {
       scheduleImplementedNotification(this, files);

pkg/analysis_server/lib/src/analysis_server_abstract.dart

@@ -299,8 +299,6 @@ abstract class AbstractAnalysisServer implements DriverProvider {
   /// [offset] of the given [file], or with `null` if there is no node at the
   /// [offset] or the node does not have an element.
   Future<Element> getElementAtOffset(String file, int offset) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     if (!priorityFiles.contains(file)) {
       var driver = getAnalysisDriver(file);
       if (driver == null) {
@@ -348,8 +346,6 @@ abstract class AbstractAnalysisServer implements DriverProvider {
   /// given [offset] of the given [file], or with `null` if there is no node as
   /// the [offset].
   Future<AstNode> getNodeAtOffset(String file, int offset) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = await getResolvedUnit(file);
     var unit = result?.unit;
     if (unit != null) {

pkg/analysis_server/lib/src/domain_abstract.dart

@@ -43,8 +43,6 @@ mixin RequestHandlerMixin<T extends AbstractAnalysisServer> {
       Map<PluginInfo, Future<plugin.Response>> futures,
       {plugin.RequestParams requestParameters,
       int timeout = 500}) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // TODO(brianwilkerson) requestParameters might need to be required.
     var endTime = DateTime.now().millisecondsSinceEpoch + timeout;
     var responses = <plugin.Response>[];

pkg/analysis_server/lib/src/domain_analysis.dart

@@ -57,8 +57,6 @@ class AnalysisDomainHandler extends AbstractRequestHandler {
 
   /// Implement the `analysis.getHover` request.
   Future<void> getHover(Request request) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var params = AnalysisGetHoverParams.fromRequest(request);
     var file = params.file;
 
@@ -87,8 +85,6 @@ class AnalysisDomainHandler extends AbstractRequestHandler {
 
   /// Implement the `analysis.getImportedElements` request.
   Future<void> getImportedElements(Request request) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var params = AnalysisGetImportedElementsParams.fromRequest(request);
     var file = params.file;
 
@@ -147,8 +143,6 @@ class AnalysisDomainHandler extends AbstractRequestHandler {
 
   /// Implement the `analysis.getNavigation` request.
   Future<void> getNavigation(Request request) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var params = AnalysisGetNavigationParams.fromRequest(request);
     var file = params.file;
     var offset = params.offset;

pkg/analysis_server/lib/src/domain_completion.dart

@@ -69,8 +69,6 @@ class CompletionDomainHandler extends AbstractRequestHandler {
     Set<String> includedElementNames,
     List<IncludedSuggestionRelevanceTag> includedSuggestionRelevanceTags,
   ) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     //
     // Allow plugins to start computing fixes.
     //

pkg/analysis_server/lib/src/domain_diagnostic.dart

@@ -37,8 +37,6 @@ class DiagnosticDomainHandler implements RequestHandler {
 
   /// Answer the `diagnostic.getServerPort` request.
   Future handleGetServerPort(Request request) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     try {
       // Open a port (or return the existing one).
       var port = await server.diagnosticServer.getServerPort();

pkg/analysis_server/lib/src/domain_execution.dart

@@ -46,8 +46,6 @@ class ExecutionDomainHandler implements RequestHandler {
 
   /// Implement the 'execution.getSuggestions' request.
   void getSuggestions(Request request) async {
-//    // TODO(brianwilkerson) Determine whether this await is necessary.
-//    await null;
 //    var params = new ExecutionGetSuggestionsParams.fromRequest(request);
 //    var computer = new RuntimeCompletionComputer(
 //        server.resourceProvider,

pkg/analysis_server/lib/src/domain_kythe.dart

@@ -28,8 +28,6 @@ class KytheDomainHandler extends AbstractRequestHandler {
 
   /// Implement the `kythe.getKytheEntries` request.
   Future<void> getKytheEntries(Request request) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var file = KytheGetKytheEntriesParams.fromRequest(request).file;
     var driver = server.getAnalysisDriver(file);
     if (driver == null) {

pkg/analysis_server/lib/src/services/completion/postfix/postfix_completion.dart

@@ -67,8 +67,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandAssert(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findAssertExpression, (expr) {
       return 'assert(${processor.utils.getNodeText(expr)});';
     }, withBraces: false);
@@ -76,16 +74,12 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandElse(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findBoolExpression,
         (expr) => 'if (${processor.makeNegatedBoolExpr(expr)})');
   }
 
   static Future<PostfixCompletion> expandFor(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findIterableExpression, (expr) {
       var value = processor.newVariable('value');
       return 'for (var $value in ${processor.utils.getNodeText(expr)})';
@@ -94,8 +88,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandFori(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findIntExpression, (expr) {
       var index = processor.newVariable('i');
       return 'for (int $index = 0; $index < ${processor.utils.getNodeText(expr)}; $index++)';
@@ -104,16 +96,12 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandIf(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findBoolExpression,
         (expr) => 'if (${processor.utils.getNodeText(expr)})');
   }
 
   static Future<PostfixCompletion> expandNegate(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findBoolExpression,
         (expr) => processor.makeNegatedBoolExpr(expr),
         withBraces: false);
@@ -121,8 +109,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandNotNull(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findObjectExpression, (expr) {
       return expr is NullLiteral
           ? 'if (false)'
@@ -132,8 +118,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandNull(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findObjectExpression, (expr) {
       return expr is NullLiteral
           ? 'if (true)'
@@ -143,8 +127,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandParen(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findObjectExpression,
         (expr) => '(${processor.utils.getNodeText(expr)})',
         withBraces: false);
@@ -152,8 +134,6 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandReturn(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findObjectExpression,
         (expr) => 'return ${processor.utils.getNodeText(expr)};',
         withBraces: false);
@@ -161,30 +141,22 @@ class DartPostfixCompletion {
 
   static Future<PostfixCompletion> expandSwitch(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findObjectExpression,
         (expr) => 'switch (${processor.utils.getNodeText(expr)})');
   }
 
   static Future<PostfixCompletion> expandTry(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expandTry(kind, processor.findStatement, withOn: false);
   }
 
   static Future<PostfixCompletion> expandTryon(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expandTry(kind, processor.findStatement, withOn: true);
   }
 
   static Future<PostfixCompletion> expandWhile(
       PostfixCompletionProcessor processor, PostfixCompletionKind kind) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     return processor.expand(kind, processor.findBoolExpression,
         (expr) => 'while (${processor.utils.getNodeText(expr)})');
   }
@@ -300,8 +272,6 @@ class PostfixCompletionProcessor {
   TypeSystem get typeSystem => completionContext.resolveResult.typeSystem;
 
   Future<PostfixCompletion> compute() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     node = _selectedNode();
     if (node == null) {
       return NO_COMPLETION;
@@ -313,8 +283,6 @@ class PostfixCompletionProcessor {
   Future<PostfixCompletion> expand(
       PostfixCompletionKind kind, Function contexter, Function sourcer,
       {bool withBraces = true}) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     AstNode expr = contexter();
     if (expr == null) {
       return null;
@@ -350,8 +318,6 @@ class PostfixCompletionProcessor {
   Future<PostfixCompletion> expandTry(
       PostfixCompletionKind kind, Function contexter,
       {bool withOn = false}) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     AstNode stmt = contexter();
     if (stmt == null) {
       return null;
@@ -455,8 +421,6 @@ class PostfixCompletionProcessor {
   }
 
   Future<bool> isApplicable() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     node = _selectedNode();
     if (node == null) {
       return false;

pkg/analysis_server/lib/src/services/completion/statement/statement_completion.dart

@@ -132,8 +132,6 @@ class StatementCompletionProcessor {
       statementContext.resolveResult.unit.declaredElement;
 
   Future<StatementCompletion> compute() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     node = _selectedNode();
     if (node == null) {
       return NO_COMPLETION;

pkg/analysis_server/lib/src/services/refactoring/convert_getter_to_method.dart

@@ -46,8 +46,6 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
 
   @override
   Future<SourceChange> createChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     change = SourceChange(refactoringName);
     // function
     if (element.enclosingElement is CompilationUnitElement) {
@@ -59,8 +57,6 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
       FieldElement field = element.variable;
       var elements = await getHierarchyMembers(searchEngine, field);
       await Future.forEach(elements, (ClassMemberElement member) async {
-        // TODO(brianwilkerson) Determine whether this await is necessary.
-        await null;
         if (member is FieldElement) {
           var getter = member.getter;
           if (!getter.isSynthetic) {
@@ -84,8 +80,6 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
 
   Future<void> _updateElementDeclaration(
       PropertyAccessorElement element) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // prepare "get" keyword
     Token getKeyword;
     {
@@ -115,8 +109,6 @@ class ConvertGetterToMethodRefactoringImpl extends RefactoringImpl
   }
 
   Future _updateElementReferences(Element element) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var matches = await searchEngine.searchReferences(element);
     var references = getSourceReferences(matches);
     for (var reference in references) {

pkg/analysis_server/lib/src/services/refactoring/convert_method_to_getter.dart

@@ -39,8 +39,6 @@ class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // check Element type
     if (element is FunctionElement) {
       if (element.enclosingElement is! CompilationUnitElement) {
@@ -67,8 +65,6 @@ class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
 
   @override
   Future<SourceChange> createChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     change = SourceChange(refactoringName);
     // FunctionElement
     if (element is FunctionElement) {
@@ -80,8 +76,6 @@ class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
       MethodElement method = element;
       var elements = await getHierarchyMembers(searchEngine, method);
       await Future.forEach(elements, (Element element) async {
-        // TODO(brianwilkerson) Determine whether this await is necessary.
-        await null;
         await _updateElementDeclaration(element);
         return _updateElementReferences(element);
       });
@@ -91,8 +85,6 @@ class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
   }
 
   Future<void> _updateElementDeclaration(Element element) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // prepare parameters
     FormalParameterList parameters;
     {
@@ -119,8 +111,6 @@ class ConvertMethodToGetterRefactoringImpl extends RefactoringImpl
   }
 
   Future<void> _updateElementReferences(Element element) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var matches = await searchEngine.searchReferences(element);
     var references = getSourceReferences(matches);
     for (var reference in references) {

pkg/analysis_server/lib/src/services/refactoring/extract_method.dart

@@ -179,8 +179,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkFinalConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     result.addStatus(validateMethodName(name));
     result.addStatus(_checkParameterNames());
@@ -191,8 +189,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     // selection
     result.addStatus(_checkSelection());
@@ -231,8 +227,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
 
   @override
   Future<SourceChange> createChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var change = SourceChange(refactoringName);
     // replace occurrences with method invocation
     for (var occurrence in _occurrences) {
@@ -431,8 +425,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
   /// Checks if created method will shadow or will be shadowed by other
   /// elements.
   Future<RefactoringStatus> _checkPossibleConflicts() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     var parent = _parentMember.parent;
     // top-level function
@@ -701,8 +693,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
   /// Prepares information about used variables, which should be turned into
   /// parameters.
   Future<RefactoringStatus> _initializeParameters() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     _parameters.clear();
     _parametersMap.clear();
     _parameterReferencesMap.clear();
@@ -766,8 +756,6 @@ class ExtractMethodRefactoringImpl extends RefactoringImpl
   }
 
   Future<void> _initializeReturnType() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var typeProvider = await resolveResult.typeProvider;
     if (_selectionFunctionExpression != null) {
       variableType = '';

pkg/analysis_server/lib/src/services/refactoring/extract_widget.dart

@@ -94,8 +94,6 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkFinalConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     result.addStatus(validateClassName(name));
     return result;
@@ -103,8 +101,6 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
 
     result.addStatus(_checkSelection());
@@ -146,8 +142,6 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
 
   @override
   Future<SourceChange> createChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var changeBuilder = DartChangeBuilder(sessionHelper.session);
     await changeBuilder.addFileEdit(resolveResult.path, (builder) {
       if (_expression != null) {
@@ -241,13 +235,9 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
   }
 
   Future<RefactoringStatus> _initializeClasses() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
 
     Future<ClassElement> getClass(String name) async {
-      // TODO(brianwilkerson) Determine whether this await is necessary.
-      await null;
       var element = await sessionHelper.getClass(flutter.widgetsUri, name);
       if (element == null) {
         result.addFatalError(
@@ -258,8 +248,6 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
     }
 
     Future<PropertyAccessorElement> getAccessor(String uri, String name) async {
-      // TODO(brianwilkerson) Determine whether this await is necessary.
-      await null;
       var element = await sessionHelper.getTopLevelPropertyAccessor(uri, name);
       if (element == null) {
         result.addFatalError("Unable to find 'required' in $uri");
@@ -280,8 +268,6 @@ class ExtractWidgetRefactoringImpl extends RefactoringImpl
   /// Prepare referenced local variables and fields, that should be turned
   /// into the widget class fields and constructor parameters.
   Future<RefactoringStatus> _initializeParameters() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     _ParametersCollector collector;
     if (_expression != null) {
       var localRange = range.node(_expression);

pkg/analysis_server/lib/src/services/refactoring/inline_local.dart

@@ -63,8 +63,6 @@ class InlineLocalRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     // prepare variable
     {

pkg/analysis_server/lib/src/services/refactoring/inline_method.dart

@@ -263,8 +263,6 @@ class InlineMethodRefactoringImpl extends RefactoringImpl
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     // prepare method information
     result.addStatus(await _prepareMethod());
@@ -311,8 +309,6 @@ class InlineMethodRefactoringImpl extends RefactoringImpl
 
   /// Initializes [_methodElement] and related fields.
   Future<RefactoringStatus> _prepareMethod() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     _methodElement = null;
     _methodParameters = null;
     _methodBody = null;
@@ -423,8 +419,6 @@ class _ReferenceProcessor {
   _ReferenceProcessor(this.ref, this.reference);
 
   Future<void> init() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     refElement = reference.element;
 
     // prepare CorrectionUtils

pkg/analysis_server/lib/src/services/refactoring/refactoring_internal.dart

@@ -40,8 +40,6 @@ abstract class RefactoringImpl implements Refactoring {
 
   @override
   Future<RefactoringStatus> checkAllConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = RefactoringStatus();
     result.addStatus(await checkInitialConditions());
     if (result.hasFatalError) {

pkg/analysis_server/lib/src/services/refactoring/rename.dart

@@ -104,8 +104,6 @@ abstract class RenameRefactoringImpl extends RefactoringImpl
 
   @override
   Future<SourceChange> createChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var changeName = "$refactoringName '$oldName' to '$newName'";
     change = SourceChange(changeName);
     await fillChange();

pkg/analysis_server/lib/src/services/refactoring/rename_class_member.dart

@@ -66,8 +66,6 @@ class RenameClassMemberRefactoringImpl extends RenameRefactoringImpl {
 
   @override
   Future<RefactoringStatus> checkInitialConditions() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var result = await super.checkInitialConditions();
     if (element is MethodElement && (element as MethodElement).isOperator) {
       result.addFatalError('Cannot rename operator.');
@@ -160,8 +158,6 @@ class _ClassMemberValidator {
         elementKind = element.kind;
 
   Future<RefactoringStatus> validate() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // check if there is a member with "newName" in the same ClassElement
     for (var newNameMember in getChildren(elementClass, name)) {
       result.addError(
@@ -292,8 +288,6 @@ class _ClassMemberValidator {
 
   /// Fills [elements] with [Element]s to rename.
   Future _prepareElements() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     if (element is ClassMemberElement) {
       elements = await getHierarchyMembers(searchEngine, element);
     } else {
@@ -303,15 +297,11 @@ class _ClassMemberValidator {
 
   /// Fills [references] with all references to [elements].
   Future _prepareReferences() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     if (!isRename) {
       return Future.value();
     }
     await _prepareElements();
     await Future.forEach(elements, (Element element) async {
-      // TODO(brianwilkerson) Determine whether this await is necessary.
-      await null;
       var elementReferences = await searchEngine.searchReferences(element);
       references.addAll(elementReferences);
     });

pkg/analysis_server/lib/src/services/refactoring/rename_constructor.dart

@@ -56,8 +56,6 @@ class RenameConstructorRefactoringImpl extends RenameRefactoringImpl {
 
   @override
   Future<void> fillChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // prepare references
     var matches = await searchEngine.searchReferences(element);
     var references = getSourceReferences(matches);
@@ -110,8 +108,6 @@ class RenameConstructorRefactoringImpl extends RenameRefactoringImpl {
   }
 
   Future<void> _replaceSynthetic() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var classElement = element.enclosingElement;
 
     var result = await AnalysisSessionHelper(session)

pkg/analysis_server/lib/src/services/refactoring/rename_import.dart

@@ -48,8 +48,6 @@ class RenameImportRefactoringImpl extends RenameRefactoringImpl {
 
   @override
   Future<void> fillChange() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     // update declaration
     {
       var prefix = element.prefix;

pkg/analysis_server/lib/src/services/refactoring/rename_unit_member.dart

@@ -186,8 +186,6 @@ class _RenameUnitMemberValidator {
   }
 
   Future<RefactoringStatus> validate() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     _validateWillConflict();
     if (isRename) {
       references = await searchEngine.searchReferences(element);
@@ -271,8 +269,6 @@ class _RenameUnitMemberValidator {
 
   /// Validates if renamed [element] will shadow any [Element] named [name].
   Future _validateWillShadow() async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var declarations = await searchEngine.searchMemberDeclarations(name);
     for (var declaration in declarations) {
       var member = declaration.element;

pkg/analysis_server/lib/src/services/search/hierarchy.dart

@@ -51,8 +51,6 @@ List<Element> getClassMembers(ClassElement clazz, [String name]) {
 /// Returns a [Set] with direct subclasses of [seed].
 Future<Set<ClassElement>> getDirectSubClasses(
     SearchEngine searchEngine, ClassElement seed) async {
-  // TODO(brianwilkerson) Determine whether this await is necessary.
-  await null;
   var matches = await searchEngine.searchSubtypes(seed);
   return matches.map((match) => match.element).cast<ClassElement>().toSet();
 }
@@ -83,8 +81,6 @@ List<Element> getExtensionMembers(ExtensionElement extension, [String name]) {
 /// their subclasses.
 Future<Set<ClassMemberElement>> getHierarchyMembers(
     SearchEngine searchEngine, ClassMemberElement member) async {
-  // TODO(brianwilkerson) Determine whether this await is necessary.
-  await null;
   Set<ClassMemberElement> result = HashSet<ClassMemberElement>();
   // extension member
   if (member.enclosingElement is ExtensionElement) {
@@ -125,8 +121,6 @@ Future<Set<ClassMemberElement>> getHierarchyMembers(
 /// corresponding named parameters in the method hierarchy.
 Future<List<ParameterElement>> getHierarchyNamedParameters(
     SearchEngine searchEngine, ParameterElement element) async {
-  // TODO(brianwilkerson) Determine whether this await is necessary.
-  await null;
   if (element.isNamed) {
     var method = element.enclosingElement;
     if (method is MethodElement) {

pkg/analysis_server/lib/src/services/search/search_engine_internal.dart

@@ -18,8 +18,6 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<Set<String>> membersOfSubtypes(ClassElement type) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var drivers = _drivers.toList();
     var searchedFiles = _createSearchedFiles(drivers);
 
@@ -29,8 +27,6 @@ class SearchEngineImpl implements SearchEngine {
     var members = <String>{};
 
     Future<void> addMembers(ClassElement type, SubtypeResult subtype) async {
-      // TODO(brianwilkerson) Determine whether this await is necessary.
-      await null;
       if (subtype != null && !visitedIds.add(subtype.id)) {
         return;
       }
@@ -57,13 +53,9 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<Set<ClassElement>> searchAllSubtypes(ClassElement type) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allSubtypes = <ClassElement>{};
 
     Future<void> addSubtypes(ClassElement type) async {
-      // TODO(brianwilkerson) Determine whether this await is necessary.
-      await null;
       var directResults = await _searchDirectSubtypes(type);
       for (var directResult in directResults) {
         var directSubtype = directResult.enclosingElement as ClassElement;
@@ -79,8 +71,6 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<List<SearchMatch>> searchMemberDeclarations(String name) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allDeclarations = <SearchMatch>[];
     var drivers = _drivers.toList();
     for (var driver in drivers) {
@@ -92,8 +82,6 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<List<SearchMatch>> searchMemberReferences(String name) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allResults = <SearchResult>[];
     var drivers = _drivers.toList();
     var searchedFiles = _createSearchedFiles(drivers);
@@ -107,8 +95,6 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<List<SearchMatch>> searchReferences(Element element) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allResults = <SearchResult>[];
     var drivers = _drivers.toList();
     var searchedFiles = _createSearchedFiles(drivers);
@@ -121,16 +107,12 @@ class SearchEngineImpl implements SearchEngine {
 
   @override
   Future<List<SearchMatch>> searchSubtypes(ClassElement type) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var results = await _searchDirectSubtypes(type);
     return results.map(SearchMatchImpl.forSearchResult).toList();
   }
 
   @override
   Future<List<SearchMatch>> searchTopLevelDeclarations(String pattern) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allElements = <Element>{};
     var regExp = RegExp(pattern);
     var drivers = _drivers.toList();
@@ -152,8 +134,6 @@ class SearchEngineImpl implements SearchEngine {
   }
 
   Future<List<SearchResult>> _searchDirectSubtypes(ClassElement type) async {
-    // TODO(brianwilkerson) Determine whether this await is necessary.
-    await null;
     var allResults = <SearchResult>[];
     var drivers = _drivers.toList();
     var searchedFiles = _createSearchedFiles(drivers);