FunctionState doesn't need to know AstNodeFactory.

src/parsing/preparser.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_PARSING_PREPARSER_H
 #define V8_PARSING_PREPARSER_H
 
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
 #include "src/base/hashmap.h"
@@ skipping 1031 matching lines @@
     DCHECK_NULL(scope_state_);
     Scope* scope = NewScriptScope();
 
     // ModuleDeclarationInstantiation for Source Text Module Records creates a
     // new Module Environment Record whose outer lexical environment record is
     // the global scope.
     if (is_module) {
       scope = NewScopeWithParent(scope, MODULE_SCOPE);
     }
 
-    PreParserFactory factory(nullptr);
     FunctionState top_scope(&function_state_, &scope_state_, scope,
-                            kNormalFunction, &factory);
+                            kNormalFunction);
     bool ok = true;
     int start_position = scanner()->peek_location().beg_pos;
     parsing_module_ = is_module;
     ParseStatementList(Token::EOS, &ok);
     if (stack_overflow()) return kPreParseStackOverflow;
     if (!ok) {
       ReportUnexpectedToken(scanner()->current_token());
     } else if (is_strict(this->scope()->language_mode())) {
       CheckStrictOctalLiteral(start_position, scanner()->location().end_pos,
                               &ok);
@@ skipping 202 matching lines @@
     const PreParserFormalParameters& parameters, FunctionKind kind,
     FunctionLiteral::FunctionType function_type, bool* ok) {
   return pre_parser_->ParseEagerFunctionBody(function_name, pos, parameters,
                                              kind, function_type, ok);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PREPARSER_H