Decouple root visitors from object visitors.

src/bootstrapper.cc

 // Copyright 2014 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.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/ieee754.h"
 #include "src/code-stubs.h"
@@ skipping 252 matching lines @@
   Handle<Map> sloppy_function_map_writable_prototype_;
   Handle<Map> strict_function_map_writable_prototype_;
   Handle<Map> class_function_map_;
   Handle<JSFunction> strict_poison_function_;
   Handle<JSFunction> restricted_function_properties_thrower_;
 
   BootstrapperActive active_;
   friend class Bootstrapper;
 };
 
-
-void Bootstrapper::Iterate(ObjectVisitor* v) {
+void Bootstrapper::Iterate(RootVisitor* v) {
   extensions_cache_.Iterate(v);
   v->Synchronize(VisitorSynchronization::kExtensions);
 }
 
 Handle<Context> Bootstrapper::CreateEnvironment(
     MaybeHandle<JSGlobalProxy> maybe_global_proxy,
     v8::Local<v8::ObjectTemplate> global_proxy_template,
     v8::ExtensionConfiguration* extensions, size_t context_snapshot_index,
     v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer,
     GlobalContextType context_type) {
@@ skipping 4974 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8