Get rid of isolate state.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index c37464c9bcd6e9cc5c2fbf34347cc68b2cff4398..f26fd77ff87807546dee5b1a0d4cd3533bf6b3af 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -543,6 +543,10 @@ class Heap {
   // jslimit_/real_jslimit_ variable in the StackGuard.
   void SetStackLimits();
 
+  // Notifies the heap that is ok to start marking or other activities that
+  // should not happen during deserialization.
+  void NotifyDeserializationComplete();
+
   // Returns whether SetUp has been called.
   bool HasBeenSetUp();
 
@@ -1378,6 +1382,8 @@ class Heap {
   inline void OnMoveEvent(HeapObject* target, HeapObject* source,
                           int size_in_bytes);
 
+  bool deserialization_complete() const { return deserialization_complete_; }
+
  protected:
   // Methods made available to tests.
 
@@ -2034,6 +2040,8 @@ class Heap {
 
   int gc_callbacks_depth_;
 
+  bool deserialization_complete_;
+
   friend class AlwaysAllocateScope;
   friend class Deserializer;
   friend class Factory;