Fix deprecation hints

pkg/analysis_server/bin/dartdeps.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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:args/args.dart';
 import 'package:analysis_server/src/analysis_manager.dart';
 
@@ skipping 10 matching lines @@
         }
       });
 }
 
 /**
  * Instances of [_DartDependencyAnalyzer] launch an analysis server and use
  * that server to analyze the dependencies of an application.
  */
 class _DartDependencyAnalyzer {
   /**
-   * The name of the application that is used to start the analyzer.
+   * The name of the application that is used to start the dependency analyzer.
    */
   static const BINARY_NAME = 'dartdeps';
 
   /**
    * The name of the option used to specify the Dart SDK.
    */
   static const String DART_SDK_OPTION = 'dart-sdk';
 
   /**
    * The name of the option used to print usage information.
@@ skipping 131 matching lines @@
     }
   }
 
   /**
    * Print information about how to use the server.
    */
   void printUsage(ArgParser parser) {
     print('Usage: $BINARY_NAME [flags] <application_directory>');
     print('');
     print('Supported flags are:');
-    print(parser.getUsage());
+    print(parser.usage);
   }
 }