Call PersistentHandleVisitor directly instead of using ObjectVisitor.

src/global-handles.h

Index: src/global-handles.h
diff --git a/src/global-handles.h b/src/global-handles.h
index f8bfb43dec74145f06c564571f070bade2b29eef..000fc64ecdf8326d7590811397961b066f06290d 100644
--- a/src/global-handles.h
+++ b/src/global-handles.h
@@ -131,15 +131,15 @@ class GlobalHandles {
   void IterateAllRoots(ObjectVisitor* v);
 
   // Iterates over all handles that have embedder-assigned class ID.
-  void IterateAllRootsWithClassIds(ObjectVisitor* v);
+  void IterateAllRootsWithClassIds(v8::PersistentHandleVisitor* v);
 
   // Iterates over all handles in the new space that have embedder-assigned
   // class ID.
-  void IterateAllRootsInNewSpaceWithClassIds(ObjectVisitor* v);
+  void IterateAllRootsInNewSpaceWithClassIds(v8::PersistentHandleVisitor* v);
 
   // Iterate over all handles in the new space that are weak, unmodified
   // and have class IDs
-  void IterateWeakRootsInNewSpaceWithClassIds(ObjectVisitor* v);
+  void IterateWeakRootsInNewSpaceWithClassIds(v8::PersistentHandleVisitor* v);
 
   // Iterates over all weak roots in heap.
   void IterateWeakRoots(ObjectVisitor* v);
@@ -189,9 +189,14 @@ class GlobalHandles {
 #endif  // DEBUG
 
  private:
-  explicit GlobalHandles(Isolate* isolate);
-
+  // Internal node structures.
+  class Node;
+  class NodeBlock;
+  class NodeIterator;
   class PendingPhantomCallback;
+  class PendingPhantomCallbacksSecondPassTask;
+
+  explicit GlobalHandles(Isolate* isolate);
 
   // Helpers for PostGarbageCollectionProcessing.
   static void InvokeSecondPassPhantomCallbacks(
@@ -200,12 +205,8 @@ class GlobalHandles {
   int PostMarkSweepProcessing(int initial_post_gc_processing_count);
   int DispatchPendingPhantomCallbacks(bool synchronous_second_pass);
   void UpdateListOfNewSpaceNodes();
-
-  // Internal node structures.
-  class Node;
-  class NodeBlock;
-  class NodeIterator;
-  class PendingPhantomCallbacksSecondPassTask;
+  void ApplyPersistentHandleVisitor(v8::PersistentHandleVisitor* visitor,
+                                    Node* node);
 
   Isolate* isolate_;