Sweep pages with lowest live memory first.

src/spaces.h

 // Copyright 2011 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 1785 matching lines @@
  protected:
   FreeList* free_list() { return &free_list_; }
 
   int area_size_;
 
   // Maximum capacity of this space.
   intptr_t max_capacity_;
 
   intptr_t SizeOfFirstPage();
 
+  intptr_t SweepPageWithLowestLiveMemory();
+
   // Accounting information for this space.
   AllocationStats accounting_stats_;
 
   // The dummy page that anchors the double linked list of pages.
   Page anchor_;
 
   // The space's free list.
   FreeList free_list_;
 
   // Normal allocation information.
@@ skipping 1007 matching lines @@
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SPACES_H_