Reorganize some pub libraries.

sdk/lib/_internal/pub/lib/src/validator/dependency.dart

 // Copyright (c) 2012, 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 dependency_validator;
+library pub.validator.dependency;
 
 import 'dart:async';
 
 import '../entrypoint.dart';
-import '../hosted_source.dart';
 import '../http.dart';
 import '../package.dart';
-import '../path_source.dart';
+import '../source/hosted.dart';
+import '../source/path.dart';
 import '../utils.dart';
 import '../validator.dart';
 import '../version.dart';
 
 /// A validator that validates a package's dependencies.
 class DependencyValidator extends Validator {
   DependencyValidator(Entrypoint entrypoint)
     : super(entrypoint);
 
   Future validate() {
@@ skipping 68 matching lines @@
   }
 
   /// Returns the suggested version constraint for a dependency that was tested
   /// against [version].
   String _constraintForVersion(Version version) {
     if (version.major != 0) return '">=$version <${version.major + 1}.0.0"';
     return '">=$version <${version.major}.${version.minor}.'
         '${version.patch + 1}"';
   }
 }