Fix Heap::Shrink to ensure that it does not free pages that are still in use.

src/mark-compact.cc

 // 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 3529 matching lines @@
     }
 
     switch (sweeper) {
       case CONSERVATIVE: {
         SweepConservatively(space, p);
         break;
       }
       case LAZY_CONSERVATIVE: {
         freed_bytes += SweepConservatively(space, p);
         if (freed_bytes >= newspace_size && p != space->LastPage()) {
-          space->SetPagesToSweep(p->next_page(), space->anchor());
+          space->SetPagesToSweep(p->next_page());
           lazy_sweeping_active = true;
         }
         break;
       }
       case PRECISE: {
         if (space->identity() == CODE_SPACE) {
           SweepPrecisely<SWEEP_ONLY, REBUILD_SKIP_LIST>(space, p, NULL);
         } else {
           SweepPrecisely<SWEEP_ONLY, IGNORE_SKIP_LIST>(space, p, NULL);
         }
@@ skipping 212 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal