Make AnalysisSErver APIs to access unit/node/element asynchronous.

pkg/analysis_server/lib/src/domain_analysis.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library domain.analysis;
 
 import 'dart:async';
 import 'dart:core';
 
 import 'package:analysis_server/plugin/analysis/analysis_domain.dart';
@@ skipping 77 matching lines @@
    */
   Future<Null> getHover(Request request) async {
     var params = new AnalysisGetHoverParams.fromRequest(request);
 
     // Prepare the resolved units.
     CompilationUnit unit;
     if (server.options.enableNewAnalysisDriver) {
       AnalysisResult result = await server.getAnalysisResult(params.file);
       unit = result?.unit;
     } else {
-      unit = server.getResolvedCompilationUnit(params.file);
+      unit = await server.getResolvedCompilationUnit(params.file);
     }
 
     // Prepare the hovers.
     List<HoverInformation> hovers = <HoverInformation>[];
     if (unit != null) {
       HoverInformation hoverInformation =
           new DartUnitHoverComputer(unit, params.offset).compute();
       if (hoverInformation != null) {
         hovers.add(hoverInformation);
       }
@@ skipping 28 matching lines @@
       // TODO(scheglov) implement for the new analysis driver
       return new Response.getNavigationInvalidFile(request);
     }
     var params = new AnalysisGetNavigationParams.fromRequest(request);
     String file = params.file;
     Future<AnalysisDoneReason> analysisFuture =
         server.onFileAnalysisComplete(file);
     if (analysisFuture == null) {
       return new Response.getNavigationInvalidFile(request);
     }
-    analysisFuture.then((AnalysisDoneReason reason) {
+    analysisFuture.then((AnalysisDoneReason reason) async {
       switch (reason) {
         case AnalysisDoneReason.COMPLETE:
-          CompilationUnit unit = server.getResolvedCompilationUnit(file);
+          CompilationUnit unit = await server.getResolvedCompilationUnit(file);
           if (unit == null) {
             server.sendResponse(new Response.getNavigationInvalidFile(request));
           } else {
             CompilationUnitElement unitElement = unit.element;
             NavigationCollectorImpl collector = computeNavigation(
                 server,
                 unitElement.context,
                 unitElement.source,
                 params.offset,
                 params.length);
@@ skipping 252 matching lines @@
       context.onResultChanged(descriptor).listen((result) {
         StreamController<engine.ResultChangedEvent> controller =
             controllers[result.descriptor];
         if (controller != null) {
           controller.add(result);
         }
       });
     }
   }
 }