Turn on the new task model by default in analysis server.

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 188 matching lines @@
    * The name of the option used to set the identifier for the client.
    */
   static const String CLIENT_ID = "client-id";
 
   /**
    * The name of the option used to set the version for the client.
    */
   static const String CLIENT_VERSION = "client-version";
 
   /**
+   * The name of the option used to disable the use of the new task model.
+   */
+  static const String DISABLE_NEW_TASK_MODEL = "disable-new-task-model";
+
+  /**
    * The name of the option used to enable incremental resolution of API
    * changes.
    */
   static const String ENABLE_INCREMENTAL_RESOLUTION_API =
       "enable-incremental-resolution-api";
 
   /**
    * The name of the option used to enable instrumentation.
    */
   static const String ENABLE_INSTRUMENTATION_OPTION = "enable-instrumentation";
 
   /**
-   * The name of the option used to enable the use of the new task model.
-   */
-  static const String ENABLE_NEW_TASK_MODEL = "enable-new-task-model";
-
-  /**
    * The name of the option used to set the file read mode.
    */
   static const String FILE_READ_MODE = "file-read-mode";
 
   /**
    * The name of the option used to print usage information.
    */
   static const String HELP_OPTION = "help";
 
   /**
@@ skipping 152 matching lines @@
       }
     }
     InstrumentationService service =
         new InstrumentationService(instrumentationServer);
     service.logVersion(_readUuid(service), results[CLIENT_ID],
         results[CLIENT_VERSION], AnalysisServer.VERSION, defaultSdk.sdkVersion);
     AnalysisEngine.instance.instrumentationService = service;
     //
     // Enable the new task model, if appropriate.
     //
-    if (results[ENABLE_NEW_TASK_MODEL]) {
-      AnalysisEngine.instance.useTaskModel = true;
-    }
+    AnalysisEngine.instance.useTaskModel = !results[DISABLE_NEW_TASK_MODEL];
     //
     // Process all of the plugins so that extensions are registered.
     //
     ServerPlugin serverPlugin = new ServerPlugin();
     List<Plugin> plugins = <Plugin>[];
     plugins.add(AnalysisEngine.instance.enginePlugin);
     plugins.add(serverPlugin);
     plugins.addAll(_userDefinedPlugins);
     ExtensionManager manager = new ExtensionManager();
     manager.processPlugins(plugins);
@@ skipping 52 matching lines @@
 
   /**
    * Create and return the parser used to parse the command-line arguments.
    */
   CommandLineParser _createArgParser() {
     CommandLineParser parser =
         new CommandLineParser(alwaysIgnoreUnrecognized: true);
     parser.addOption(CLIENT_ID,
         help: "an identifier used to identify the client");
     parser.addOption(CLIENT_VERSION, help: "the version of the client");
+    parser.addFlag(DISABLE_NEW_TASK_MODEL,
+        help: "disable the use of the new task model",
+        defaultsTo: false,
+        hide: true,
+        negatable: false);
     parser.addFlag(ENABLE_INCREMENTAL_RESOLUTION_API,
         help: "enable using incremental resolution for API changes",
         defaultsTo: false,
         negatable: false);
     parser.addFlag(ENABLE_INSTRUMENTATION_OPTION,
         help: "enable sending instrumentation information to a server",
         defaultsTo: false,
         negatable: false);
-    parser.addFlag(ENABLE_NEW_TASK_MODEL,
-        help: "enable the use of the new task model",
-        defaultsTo: false,
-        hide: true,
-        negatable: false);
     parser.addFlag(HELP_OPTION,
         help: "print this help message without starting a server",
         defaultsTo: false,
         negatable: false);
     parser.addOption(INCREMENTAL_RESOLUTION_LOG,
         help: "the description of the incremental resolution log");
     parser.addFlag(INCREMENTAL_RESOLUTION_VALIDATION,
         help: "enable validation of incremental resolution results (slow)",
         defaultsTo: false,
         negatable: false);
@@ skipping 69 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;
   }
 }