First pass of ImageWriter

Change-Id: I4f189587a2e3cc1c265200b8fa64321b299947eb
diff --git a/src/mark_stack.h b/src/mark_stack.h
index eeeb79c..38252c2 100644
--- a/src/mark_stack.h
+++ b/src/mark_stack.h
@@ -5,6 +5,8 @@
 
 #include "logging.h"
 #include "macros.h"
+#include "mem_map.h"
+#include "scoped_ptr.h"
 
 namespace art {
 
@@ -41,6 +43,9 @@
 
   bool Init(size_t maximum_size);
 
+  // Memory mapping of the mark stack.
+  scoped_ptr<MemMap> mem_map_;
+
   // Base of the mark stack.
   const Object* const* base_;