Replace try/finally with PerformanceTag.makeCurrentWhile().

pkg/analysis_server/lib/src/analysis_server.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 analysis.server;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:math' show max;
 
@@ skipping 554 matching lines @@
     File file = resourceProvider.getResource(path);
     return ContextManager.createSourceInContext(getAnalysisContext(path), file);
   }
 
   /**
    * Handle a [request] that was read from the communication channel.
    */
   void handleRequest(Request request) {
     _performance.logRequest(request);
     runZoned(() {
-      PerformanceTag prevTag =
-          ServerPerformanceStatistics.serverRequests.makeCurrent();
-      try {
+      ServerPerformanceStatistics.serverRequests.makeCurrentWhile(() {
         int count = handlers.length;
         for (int i = 0; i < count; i++) {
           try {
             Response response = handlers[i].handleRequest(request);
             if (response == Response.DELAYED_RESPONSE) {
               return;
             }
             if (response != null) {
               channel.sendResponse(response);
               return;
             }
           } on RequestFailure catch (exception) {
             channel.sendResponse(exception.response);
             return;
           } catch (exception, stackTrace) {
             RequestError error =
                 new RequestError(RequestErrorCode.SERVER_ERROR, exception.toString());
             if (stackTrace != null) {
               error.stackTrace = stackTrace.toString();
             }
             Response response = new Response(request.id, error: error);
             channel.sendResponse(response);
             return;
           }
         }
         channel.sendResponse(new Response.unknownRequest(request));
-      } finally {
-        prevTag.makeCurrent();
-      }
+      });
     }, onError: (exception, stackTrace) {
       sendServerErrorNotification(exception, stackTrace, fatal: true);
     });
   }
 
   /**
    * Returns `true` if there is a subscription for the given [service] and
    * [file].
    */
   bool hasAnalysisSubscription(AnalysisService service, String file) {
@@ skipping 714 matching lines @@
  * Container with global [AnalysisServer] performance statistics.
  */
 class ServerPerformanceStatistics {
   /**
    * The [PerformanceTag] for time spent in [ExecutionDomainHandler].
    */
   static PerformanceTag executionNotifications =
       new PerformanceTag('executionNotifications');
 
   /**
-   * The [PerformanceTag] for time spent in
-   * PerformAnalysisOperation._updateIndex.
-   */
-  static PerformanceTag index = new PerformanceTag('index');
-
-  /**
    * The [PerformanceTag] for time spent performing a _DartIndexOperation.
    */
   static PerformanceTag indexOperation = new PerformanceTag('indexOperation');
 
   /**
    * The [PerformanceTag] for time spent between calls to
    * AnalysisServer.performOperation when the server is not idle.
    */
   static PerformanceTag intertask = new PerformanceTag('intertask');
 
@@ skipping 12 matching lines @@
   /**
    * The [PerformanceTag] for time spent in server comminication channels.
    */
   static PerformanceTag serverChannel = new PerformanceTag('serverChannel');
 
   /**
    * The [PerformanceTag] for time spent in server request handlers.
    */
   static PerformanceTag serverRequests = new PerformanceTag('serverRequests');
 }