--- old/src/share/vm/memory/strongRootsScope.hpp	2015-04-01 12:45:25.111899612 +0200
+++ new/src/share/vm/memory/strongRootsScope.hpp	2015-04-01 12:45:24.999899617 +0200
@@ -25,17 +25,24 @@
 #ifndef SHARE_VM_MEMORY_STRONGROOTSSCOPE_HPP
 #define SHARE_VM_MEMORY_STRONGROOTSSCOPE_HPP
 
-#include "memory/iterator.hpp"
-
 // Some collectors will perform "process_strong_roots" in parallel.
 // Such a call will involve claiming some fine-grained tasks, such as
 // scanning of threads and code blobs.
 // Claiming of these tasks requires that sequential code calls
 // initialization methods to set the claiming code in the right
 // state for parallel task claiming.
-// StrongRootsScope is a way to capture such setup code to make
-// sure that it is executed in the correct way.
-class StrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
+// StrongRootsScope and MarkScope provide ways to capture such
+// setup code to make sure that it is executed in the correct way.
+
+class MarkScope : public StackObj {
+ protected:
+  bool _active;
+ public:
+  MarkScope(bool activate = true);
+  ~MarkScope();
+};
+
+class StrongRootsScope : public MarkScope {
  public:
   StrongRootsScope(bool activate = true);
   ~StrongRootsScope();