Decouple root visitors from object visitors.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 994902ab0b46bb2c2af1c508877264a36f6a3427..536d6fe851ccaf7b7c578f86f5fc0f137e33249e 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -10660,20 +10660,17 @@ char* Relocatable::RestoreState(Isolate* isolate, char* from) {
   return from + ArchiveSpacePerThread();
 }
 
-
-char* Relocatable::Iterate(ObjectVisitor* v, char* thread_storage) {
+char* Relocatable::Iterate(RootVisitor* v, char* thread_storage) {
   Relocatable* top = *reinterpret_cast<Relocatable**>(thread_storage);
   Iterate(v, top);
   return thread_storage + ArchiveSpacePerThread();
 }
 
-
-void Relocatable::Iterate(Isolate* isolate, ObjectVisitor* v) {
+void Relocatable::Iterate(Isolate* isolate, RootVisitor* v) {
   Iterate(v, isolate->relocatable_top());
 }
 
-
-void Relocatable::Iterate(ObjectVisitor* v, Relocatable* top) {
+void Relocatable::Iterate(RootVisitor* v, Relocatable* top) {
   Relocatable* current = top;
   while (current != NULL) {
     current->IterateInstance(v);
@@ -13874,22 +13871,6 @@ Code* SharedFunctionInfo::SearchOptimizedCodeMap(Context* native_context,
 }
 
 
-#define DECLARE_TAG(ignore1, name, ignore2) name,
-const char* const VisitorSynchronization::kTags[
-    VisitorSynchronization::kNumberOfSyncTags] = {
-  VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_TAG)
-};
-#undef DECLARE_TAG
-
-
-#define DECLARE_TAG(ignore1, ignore2, name) name,
-const char* const VisitorSynchronization::kTagNames[
-    VisitorSynchronization::kNumberOfSyncTags] = {
-  VISITOR_SYNCHRONIZATION_TAGS_LIST(DECLARE_TAG)
-};
-#undef DECLARE_TAG
-
-
 void ObjectVisitor::VisitCodeTarget(RelocInfo* rinfo) {
   DCHECK(RelocInfo::IsCodeTarget(rinfo->rmode()));
   Object* old_pointer = Code::GetCodeFromTargetAddress(rinfo->target_address());