remove unused imports

pkg/analyzer/lib/source/pub_package_map_provider.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 source.pub_package_map_provider;
 
 import 'dart:collection';
 import 'dart:convert';
 import 'dart:io' as io;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/source/package_map_provider.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
-import 'package:path/path.dart';
 
 /**
  * The function used to run pub list.
  */
 typedef io.ProcessResult RunPubList(Folder folder);
 
 /**
  * Implementation of PackageMapProvider that operates by executing pub.
  */
 class PubPackageMapProvider implements PackageMapProvider {
@@ skipping 129 matching lines @@
   /**
    * Run pub list to determine the packages and input files.
    */
   io.ProcessResult _runPubListDefault(Folder folder) {
     return io.Process.runSync(
         sdk.pubExecutable.getAbsolutePath(),
         [PUB_LIST_COMMAND],
         workingDirectory: folder.path);
   }
 }