Made iteration of global handles more efficient on scavenges.

src/heap.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 711 matching lines @@
     return String::cast(roots_[k##name##RootIndex]);                           \
   }
   SYMBOL_LIST(SYMBOL_ACCESSOR)
 #undef SYMBOL_ACCESSOR
 
   // The hidden_symbol is special because it is the empty string, but does
   // not match the empty string.
   static String* hidden_symbol() { return hidden_symbol_; }
 
   // Iterates over all roots in the heap.
-  static void IterateRoots(ObjectVisitor* v);
+  static void IterateRoots(ObjectVisitor* v, VisitMode mode);
   // Iterates over all strong roots in the heap.
-  static void IterateStrongRoots(ObjectVisitor* v);
+  static void IterateStrongRoots(ObjectVisitor* v, VisitMode mode);
 
   // Iterates remembered set of an old space.
   static void IterateRSet(PagedSpace* space, ObjectSlotCallback callback);
 
   // Iterates a range of remembered set addresses starting with rset_start
   // corresponding to the range of allocated pointers
   // [object_start, object_end).
   // Returns the number of bits that were set.
   static int IterateRSetRange(Address object_start,
                               Address object_end,
@@ skipping 893 matching lines @@
   }
   static TranscendentalCache* caches_[kNumberOfCaches];
   Element elements_[kCacheSize];
   Type type_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_