Wait for InstrumentationService.shutdown() before exit(0).

pkg/analysis_server/lib/src/server/driver.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 driver;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:math';
 
@@ skipping 410 matching lines @@
         serverPlugin, packageResolverProvider);
     httpServer = new HttpAnalysisServer(socketServer);
     stdioServer = new StdioAnalysisServer(socketServer);
     socketServer.userDefinedPlugins = _userDefinedPlugins;
 
     if (serve_http) {
       httpServer.serveHttp(port);
     }
 
     _captureExceptions(service, () {
-      stdioServer.serveStdio().then((_) {
+      stdioServer.serveStdio().then((_) async {
         if (serve_http) {
           httpServer.close();
         }
-        service.shutdown();
+        await service.shutdown();
         exit(0);
       });
     },
         print:
             results[INTERNAL_PRINT_TO_CONSOLE] ? null : httpServer.recordPrint);
   }
 
   /**
    * Execute the given [callback] within a zone that will capture any unhandled
    * exceptions and both report them to the client and send them to the given
@@ skipping 125 matching lines @@
       uuidFile.parent.createSync(recursive: true);
       uuidFile.writeAsStringSync(uuid);
     } catch (exception, stackTrace) {
       service.logPriorityException(exception, stackTrace);
       // Slightly alter the uuid to indicate it was not persisted
       uuid = 'temp-$uuid';
     }
     return uuid;
   }
 }