Clean up package imports and library names

pkg/analyzer/lib/source/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.package_map_provider;
+library analyzer.source.package_map_provider;
 
 import 'package:analyzer/file_system/file_system.dart';
 
 /**
  * Data structure output by PackageMapProvider.  This contains both the package
  * map and dependency information.
  */
 class PackageMapInfo {
   /**
    * The package map itself.  This is a map from package name to a list of
@@ skipping 19 matching lines @@
  */
 abstract class PackageMapProvider {
   /**
    * Compute a package map for the given folder, if possible.
    *
    * If a package map can't be computed (e.g. because an error occurred), a
    * [PackageMapInfo] will still be returned, but its packageMap will be null.
    */
   PackageMapInfo computePackageMap(Folder folder);
 }