Compact map space when doing mark-sweep if after collection size of map space...

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 786 matching lines @@
   static inline void ScavengeObject(HeapObject** p, HeapObject* object);
 
   // Clear a range of remembered set addresses corresponding to the object
   // area address 'start' with size 'size_in_bytes', eg, when adding blocks
   // to the free list.
   static void ClearRSetRange(Address start, int size_in_bytes);
 
   // Rebuild remembered set in old and map spaces.
   static void RebuildRSets();
 
+  // Update an old object's remembered set
+  static int UpdateRSet(HeapObject* obj);
+
   // Commits from space if it is uncommitted.
   static void EnsureFromSpaceIsCommitted();
 
   //
   // Support for the API.
   //
 
   static bool CreateApiObjects();
 
   // Attempt to find the number in a small cache.  If we finds it, return
@@ skipping 250 matching lines @@
   static inline bool ShouldBePromoted(Address old_address, int object_size);
 #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
   // Record the copy of an object in the NewSpace's statistics.
   static void RecordCopiedObject(HeapObject* obj);
 
   // Record statistics before and after garbage collection.
   static void ReportStatisticsBeforeGC();
   static void ReportStatisticsAfterGC();
 #endif
 
-  // Update an old object's remembered set
-  static int UpdateRSet(HeapObject* obj);
-
   // Rebuild remembered set in an old space.
   static void RebuildRSets(PagedSpace* space);
 
   // Rebuild remembered set in the large object space.
   static void RebuildRSets(LargeObjectSpace* space);
 
   // Slow part of scavenge object.
   static void ScavengeObjectSlow(HeapObject** p, HeapObject* object);
 
   // Copy memory from src to dst.
@@ skipping 139 matching lines @@
 class OldSpaces BASE_EMBEDDED {
  public:
   OldSpace* next();
   OldSpaces() { counter_ = OLD_POINTER_SPACE; }
  private:
   int counter_;
 };
 
 
 // Space iterator for iterating over all the paged spaces of the heap:
-// Map space, old pointer space, old data space and code space.
+// Map space, old pointer space, old data space, code space and cell space.
 // Returns each space in turn, and null when it is done.
 class PagedSpaces BASE_EMBEDDED {
  public:
   PagedSpace* next();
   PagedSpaces() { counter_ = OLD_POINTER_SPACE; }
  private:
   int counter_;
 };
 
 
@@ skipping 430 matching lines @@
 
   // To speed up scavenge collections new space string are kept
   // separate from old space strings.
   static List<Object*> new_space_strings_;
   static List<Object*> old_space_strings_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_