Decouple root visitors from object visitors.

src/global-handles.h

Index: src/global-handles.h
diff --git a/src/global-handles.h b/src/global-handles.h
index 000fc64ecdf8326d7590811397961b066f06290d..673f1547b99f0e6325f2d86672a8a1edd349de26 100644
--- a/src/global-handles.h
+++ b/src/global-handles.h
@@ -18,7 +18,7 @@ namespace v8 {
 namespace internal {
 
 class HeapStats;
-class ObjectVisitor;
+class RootVisitor;
 
 // Structure for tracking global handles.
 // A single list keeps all the allocated global handles.
@@ -125,10 +125,10 @@ class GlobalHandles {
       GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags);
 
   // Iterates over all strong handles.
-  void IterateStrongRoots(ObjectVisitor* v);
+  void IterateStrongRoots(RootVisitor* v);
 
   // Iterates over all handles.
-  void IterateAllRoots(ObjectVisitor* v);
+  void IterateAllRoots(RootVisitor* v);
 
   // Iterates over all handles that have embedder-assigned class ID.
   void IterateAllRootsWithClassIds(v8::PersistentHandleVisitor* v);
@@ -142,7 +142,7 @@ class GlobalHandles {
   void IterateWeakRootsInNewSpaceWithClassIds(v8::PersistentHandleVisitor* v);
 
   // Iterates over all weak roots in heap.
-  void IterateWeakRoots(ObjectVisitor* v);
+  void IterateWeakRoots(RootVisitor* v);
 
   // Find all weak handles satisfying the callback predicate, mark
   // them as pending.
@@ -154,7 +154,7 @@ class GlobalHandles {
   // may also include old space objects).
 
   // Iterates over strong and dependent handles. See the node above.
-  void IterateNewSpaceStrongAndDependentRoots(ObjectVisitor* v);
+  void IterateNewSpaceStrongAndDependentRoots(RootVisitor* v);
 
   // Finds weak independent or partially independent handles satisfying
   // the callback predicate and marks them as pending. See the note above.
@@ -162,7 +162,7 @@ class GlobalHandles {
 
   // Iterates over weak independent or partially independent handles.
   // See the note above.
-  void IterateNewSpaceWeakIndependentRoots(ObjectVisitor* v);
+  void IterateNewSpaceWeakIndependentRoots(RootVisitor* v);
 
   // Finds weak independent or unmodified handles satisfying
   // the callback predicate and marks them as pending. See the note above.
@@ -172,7 +172,7 @@ class GlobalHandles {
   // Iterates over weak independent or unmodified handles.
   // See the note above.
   template <IterationMode mode>
-  void IterateNewSpaceWeakUnmodifiedRoots(ObjectVisitor* v);
+  void IterateNewSpaceWeakUnmodifiedRoots(RootVisitor* v);
 
   // Identify unmodified objects that are in weak state and marks them
   // unmodified
@@ -304,9 +304,9 @@ class EternalHandles {
   }
 
   // Iterates over all handles.
-  void IterateAllRoots(ObjectVisitor* visitor);
+  void IterateAllRoots(RootVisitor* visitor);
   // Iterates over all handles which might be in new space.
-  void IterateNewSpaceRoots(ObjectVisitor* visitor);
+  void IterateNewSpaceRoots(RootVisitor* visitor);
   // Rebuilds new space list.
   void PostGarbageCollectionProcessing(Heap* heap);