Revert of Reland concurrent sweeping of code space.

src/heap/mark-compact.h

Index: src/heap/mark-compact.h
diff --git a/src/heap/mark-compact.h b/src/heap/mark-compact.h
index 8f68917c319bdd3382fcf0b7a3d6adfff3e928c6..b4a4fe7fda2c423c6450ee513d3d127472c0b63e 100644
--- a/src/heap/mark-compact.h
+++ b/src/heap/mark-compact.h
@@ -699,8 +699,6 @@
 
   void EnsureSweepingCompleted();
 
-  void SweepOrWaitUntilSweepingCompleted(Page* page);
-
   // If sweeper threads are not active this method will return true. If
   // this is a latency issue we should be smarter here. Otherwise, it will
   // return true if the sweeper threads are done processing the pages.
@@ -981,7 +979,6 @@
   List<Code*> invalidated_code_;
 
   base::SmartPointer<FreeList> free_list_old_space_;
-  base::SmartPointer<FreeList> free_list_code_space_;
 
   friend class Heap;
 };