Phantom references support internal fields

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 9c481b09a9d326b4bd59fdbf79d431404008dc11..644637ddfa5b94d8b77a01d81cfa8e006c21f04b 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -304,6 +304,8 @@ void MarkCompactCollector::CollectGarbage() {
 
   heap_->set_encountered_weak_cells(Smi::FromInt(0));
 
+  isolate()->global_handles()->CollectPhantomCallbackData();
+
 #ifdef VERIFY_HEAP
   if (FLAG_verify_heap) {
     VerifyMarking(heap_);
@@ -2213,10 +2215,8 @@ void MarkCompactCollector::MarkLiveObjects() {
       &IsUnmarkedHeapObject);
   // Then we mark the objects and process the transitive closure.
   heap()->isolate()->global_handles()->IterateWeakRoots(&root_visitor);
-  while (marking_deque_.overflowed()) {
-    RefillMarkingDeque();
-    EmptyMarkingDeque();
-  }
+
+  ProcessMarkingDeque();

[jochen (gone - plz use gerrit), 2014/12/02 10:25:59]

this is not needed, because the following call to ProcessEphemeralMarking
processes the deque anyways

[Erik Corry, 2014/12/02 10:40:49]

I think this is wrong, and it is needed.

Nothing in the ProcessEphemeralMarking will check for an overflowed marking
deque, before the work_to_do variable is set.  That means it can be incorrectly
set to false, and the ephemeral iteration can terminate early.

 
   // Repeat host application specific and Harmony weak maps marking to
   // mark unmarked objects reachable from the weak roots.