Revert revisions 5041 and 5042 introducing virtual scavenge...

src/objects.h

Index: src/objects.h
===================================================================
--- src/objects.h	(revision 5045)
+++ src/objects.h	(working copy)
@@ -2899,7 +2899,6 @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(Code);
 };
 
-typedef void (*Scavenger)(Map* map, HeapObject** slot, HeapObject* object);
 
 // All heap objects have a Map that describes their structure.
 //  A Map contains information about:
@@ -3101,13 +3100,6 @@
   void MapVerify();
 #endif
 
-  inline Scavenger scavenger();
-  inline void set_scavenger(Scavenger callback);
-
-  inline void Scavenge(HeapObject** slot, HeapObject* obj) {
-    scavenger()(this, slot, obj);
-  }
-
   static const int kMaxPreAllocatedPropertyFields = 255;
 
   // Layout description.
@@ -3118,8 +3110,7 @@
   static const int kInstanceDescriptorsOffset =
       kConstructorOffset + kPointerSize;
   static const int kCodeCacheOffset = kInstanceDescriptorsOffset + kPointerSize;
-  static const int kIterateBodyCallbackOffset = kCodeCacheOffset + kPointerSize;
-  static const int kPadStart = kIterateBodyCallbackOffset + kPointerSize;
+  static const int kPadStart = kCodeCacheOffset + kPointerSize;
   static const int kSize = MAP_POINTER_ALIGN(kPadStart);
 
   // Layout of pointer fields. Heap iteration code relies on them