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

src/heap.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 5591 matching lines @@
 #ifdef DEBUG
   delete debug_utils_;
   debug_utils_ = NULL;
 #endif
 }
 
 
 void Heap::Shrink() {
   // Try to shrink all paged spaces.
   PagedSpaces spaces;
-  for (PagedSpace* space = spaces.next(); space != NULL; space = spaces.next())
+  for (PagedSpace* space = spaces.next();
+       space != NULL;
+       space = spaces.next()) {
     space->ReleaseAllUnusedPages();
+  }
 }
 
 
 void Heap::AddGCPrologueCallback(GCPrologueCallback callback, GCType gc_type) {
   ASSERT(callback != NULL);
   GCPrologueCallbackPair pair(callback, gc_type);
   ASSERT(!gc_prologue_callbacks_.Contains(pair));
   return gc_prologue_callbacks_.Add(pair);
 }
 
@@ skipping 828 matching lines @@
   isolate_->heap()->store_buffer()->Compact();
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal