Delete dead store buffer verification code and code that changes the store buffer in debug mode.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index b6d792cc05b49bb9a586db87615dc07c6d3db156..7a17abbe371cc8700e45fb40732185f6c3afb822 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -995,10 +995,6 @@ class Heap {
   void Print();
   void PrintHandles();
 
-  void OldPointerSpaceCheckStoreBuffer();
-  void MapSpaceCheckStoreBuffer();
-  void LargeObjectSpaceCheckStoreBuffer();
-
   // Report heap statistics.
   void ReportHeapStatistics(const char* title);
   void ReportCodeStatistics(const char* title);