Revert "Background finalization."

runtime/vm/gc_marker.cc

Index: runtime/vm/gc_marker.cc
diff --git a/runtime/vm/gc_marker.cc b/runtime/vm/gc_marker.cc
index 0b302cec79fb011d8c5dfc97364e0fdbf52646e5..069f34175990a492b4c75280f2062e1e58ad0153 100644
--- a/runtime/vm/gc_marker.cc
+++ b/runtime/vm/gc_marker.cc
@@ -422,21 +422,19 @@ static bool IsUnreachable(const RawObject* raw_obj) {
 
 class MarkingWeakVisitor : public HandleVisitor {
  public:
-  MarkingWeakVisitor(Thread* thread, FinalizationQueue* queue) :
-      HandleVisitor(thread), queue_(queue) { }
+  MarkingWeakVisitor() : HandleVisitor(Thread::Current()) {
+  }
 
   void VisitHandle(uword addr) {
     FinalizablePersistentHandle* handle =
         reinterpret_cast<FinalizablePersistentHandle*>(addr);
     RawObject* raw_obj = handle->raw();
     if (IsUnreachable(raw_obj)) {
-      handle->UpdateUnreachable(thread()->isolate(), queue_);
+      handle->UpdateUnreachable(thread()->isolate());
     }
   }
 
  private:
-  FinalizationQueue* queue_;
-
   DISALLOW_COPY_AND_ASSIGN(MarkingWeakVisitor);
 };
 
@@ -670,14 +668,8 @@ void GCMarker::MarkObjects(Isolate* isolate,
       mark.DrainMarkingStack();
       {
         TIMELINE_FUNCTION_GC_DURATION(thread, "WeakHandleProcessing");
-        FinalizationQueue* queue = new FinalizationQueue();
-        MarkingWeakVisitor mark_weak(thread, queue);
+        MarkingWeakVisitor mark_weak;
         IterateWeakRoots(isolate, &mark_weak);
-        if (queue->length() > 0) {
-          Dart::thread_pool()->Run(new BackgroundFinalizer(isolate, queue));
-        } else {
-          delete queue;
-        }
       }
       // All marking done; detach code, etc.
       FinalizeResultsFrom(&mark);
@@ -701,14 +693,8 @@ void GCMarker::MarkObjects(Isolate* isolate,
       // Phase 2: Weak processing on main thread.
       {
         TIMELINE_FUNCTION_GC_DURATION(thread, "WeakHandleProcessing");
-        FinalizationQueue* queue = new FinalizationQueue();
-        MarkingWeakVisitor mark_weak(thread, queue);
+        MarkingWeakVisitor mark_weak;
         IterateWeakRoots(isolate, &mark_weak);
-        if (queue->length() > 0) {
-          Dart::thread_pool()->Run(new BackgroundFinalizer(isolate, queue));
-        } else {
-          delete queue;
-        }
       }
       barrier.Sync();