Clean up imports in analysis_server and analyzer_cli (and one missed in analyzer)

pkg/analysis_server/lib/src/services/dependencies/library_dependencies.dart

 // Copyright (c) 2015, 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 services.dependencies.library;
 
+import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
-import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 class LibraryDependencyCollector {
   final Set<LibraryElement> _visitedLibraries = new Set<LibraryElement>();
   final Set<String> _dependencies = new Set<String>();
 
   final List<AnalysisContext> _contexts;
 
@@ skipping 16 matching lines @@
     return result;
   }
 
   Set<String> collectLibraryDependencies() {
     _contexts.forEach((AnalysisContext context) => context.librarySources
         .forEach((Source source) =>
             _addDependencies(context.getLibraryElement(source))));
     return _dependencies;
   }
 
-  Map<AnalysisContext, Folder> _reverse(Map<Folder, AnalysisContext> map) {
-    Map<AnalysisContext, Folder> reverseMap =
-        new Map<AnalysisContext, Folder>();
-    map.forEach((Folder f, AnalysisContext c) => reverseMap[c] = f);
-    return reverseMap;
-  }
-
   void _addDependencies(LibraryElement libraryElement) {
     if (libraryElement == null) {
       return;
     }
     if (_visitedLibraries.add(libraryElement)) {
       for (CompilationUnitElement cu in libraryElement.units) {
         String path = cu.source.fullName;
         if (path != null) {
           _dependencies.add(path);
         }
       }
       libraryElement.imports.forEach(
           (ImportElement import) => _addDependencies(import.importedLibrary));
       libraryElement.exports.forEach(
           (ExportElement export) => _addDependencies(export.exportedLibrary));
     }
   }
+
+  Map<AnalysisContext, Folder> _reverse(Map<Folder, AnalysisContext> map) {
+    Map<AnalysisContext, Folder> reverseMap =
+        new Map<AnalysisContext, Folder>();
+    map.forEach((Folder f, AnalysisContext c) => reverseMap[c] = f);
+    return reverseMap;
+  }
 }