update comments for http diagnostic port

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 104 matching lines @@
    */
   static const String INTERNAL_PRINT_TO_CONSOLE = "internal-print-to-console";
 
   /**
    * The name of the option used to specify if [print] should print to the
    * console instead of being intercepted.
    */
   static const String INTERNAL_DELAY_FREQUENCY = 'internal-delay-frequency';
 
   /**
-   * The name of the option used to specify the port to which the server will
-   * connect.
+   * The option for specifying the http diagnostic port.
+   * If specified, users can review server status and performance information
+   * by opening a web browser on http://localhost:<port>
    */
   static const String PORT_OPTION = "port";
 
   /**
    * The path to the SDK.
    * TODO(paulberry): get rid of this once the 'analysis.updateSdks' request is
    * operational.
    */
   static const String SDK_OPTION = "sdk";
 
@@ skipping 220 matching lines @@
     parser.addOption(
         INSTRUMENTATION_LOG_FILE,
         help: "the path of the file to which instrumentation data will be written");
     parser.addFlag(
         INTERNAL_PRINT_TO_CONSOLE,
         help: "enable sending `print` output to the console",
         defaultsTo: false,
         negatable: false);
     parser.addOption(
         PORT_OPTION,
-        help: "[port] the port on which the server will listen");
+        help: "the http diagnostic port on which the server provides"
+            " status and performance information");
     parser.addOption(INTERNAL_DELAY_FREQUENCY);
     parser.addOption(SDK_OPTION, help: "[path] the path to the sdk");
     parser.addFlag(
         NO_ERROR_NOTIFICATION,
         help: "disable sending all analysis error notifications to the server",
         defaultsTo: false,
         negatable: false);
     parser.addFlag(
         NO_INDEX,
         help: "disable indexing sources",
@@ skipping 48 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;
   }
 }