Eliminate dependencies on pkg/front_end.

pkg/analyzer_plugin/tool/spec/generate_all.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:io';
 
-import 'package:front_end/src/codegen/tools.dart';
+import 'package:analyzer/src/codegen/tools.dart';
 import 'package:path/path.dart';
 
 import 'codegen_dart_protocol.dart' as codegen_dart_protocol;
 import 'codegen_inttest_methods.dart' as codegen_inttest_methods;
 import 'codegen_matchers.dart' as codegen_matchers;
 import 'codegen_protocol_common.dart' as codegen_protocol_common;
 import 'codegen_protocol_constants.dart' as codegen_protocol_constants;
 import 'to_html.dart' as to_html;
 
 /**
@@ skipping 11 matching lines @@
 List<GeneratedContent> get allTargets {
   List<GeneratedContent> targets = <GeneratedContent>[];
   targets.add(codegen_dart_protocol.target(true));
   targets.add(codegen_inttest_methods.target);
   targets.add(codegen_matchers.target);
   targets.add(codegen_protocol_common.target(true));
   targets.add(codegen_protocol_constants.target);
   targets.add(to_html.target);
   return targets;
 }