Don't scan on scavenge dead large objects.

src/heap/store-buffer.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
 
 #include "src/v8.h"
 
 #include "src/base/atomicops.h"
 #include "src/counters.h"
@@ skipping 434 matching lines @@
     if (heap_->InNewSpace(object)) {
       if (heap_->mark_compact_collector()->IsSlotInLiveObject(
               reinterpret_cast<HeapObject**>(slot),
               reinterpret_cast<HeapObject*>(object))) {
         *new_top++ = addr;
       }
     }
   }
   old_top_ = new_top;
   ClearFilteringHashSets();
+
+  // Don't scan on scavenge dead large objects.
+  LargeObjectIterator it(heap_->lo_space());
+  for (HeapObject* object = it.Next(); object != NULL; object = it.Next()) {
+    MemoryChunk* chunk = MemoryChunk::FromAddress(object->address());
+    if (chunk->scan_on_scavenge() && !Marking::MarkBitFrom(object).Get()) {
+      chunk->set_scan_on_scavenge(false);
+    }
+  }
 }
 
 
 void StoreBuffer::VerifyValidStoreBufferEntries() {
   for (Address* current = old_start_; current < old_top_; current++) {
     Object** slot = reinterpret_cast<Object**>(*current);
     Object* object = reinterpret_cast<Object*>(
         base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(slot)));
     CHECK(heap_->InNewSpace(object));
     heap_->mark_compact_collector()->VerifyIsSlotInLiveObject(
@@ skipping 181 matching lines @@
     }
     old_buffer_is_sorted_ = false;
     old_buffer_is_filtered_ = false;
     *old_top_++ = reinterpret_cast<Address>(int_addr << kPointerSizeLog2);
     DCHECK(old_top_ <= old_limit_);
   }
   heap_->isolate()->counters()->store_buffer_compactions()->Increment();
 }
 }
 }  // namespace v8::internal