Avoid stale store buffer entries after full GC by promoting objects referenced by the store buffer.

src/heap/store-buffer.cc

Index: src/heap/store-buffer.cc
diff --git a/src/heap/store-buffer.cc b/src/heap/store-buffer.cc
index 6c8a457af811e925ca295477497da5fa311c4a13..62f57596b82745f811aa575e07531ca2bad1b654 100644
--- a/src/heap/store-buffer.cc
+++ b/src/heap/store-buffer.cc
@@ -381,6 +381,7 @@ void StoreBuffer::GCEpilogue() {
 void StoreBuffer::ProcessOldToNewSlot(Address slot_address,
                                       ObjectSlotCallback slot_callback,
                                       bool clear_maps) {
+  printf("process %p\n", slot_address);
   Object** slot = reinterpret_cast<Object**>(slot_address);
   Object* object = reinterpret_cast<Object*>(
       base::NoBarrier_Load(reinterpret_cast<base::AtomicWord*>(slot)));
@@ -401,6 +402,7 @@ void StoreBuffer::ProcessOldToNewSlot(Address slot_address,
     // Unfortunately, we do not know about the slot. It could be in a
     // just freed free space object.
     if (heap_->InToSpace(object)) {
+      printf("enter directly  %p\n", slot);
       EnterDirectlyIntoStoreBuffer(reinterpret_cast<Address>(slot));
     }
   }