diff -r 48a02303574e -r 9d02451b536e src/hotspot/share/gc/shared/collectedHeap.hpp
--- a/src/hotspot/share/gc/shared/collectedHeap.hpp	Wed Mar 13 11:31:00 2019 +0100
+++ b/src/hotspot/share/gc/shared/collectedHeap.hpp	Wed Mar 13 11:31:00 2019 +0100
@@ -450,11 +450,6 @@
   // non-object.
   virtual HeapWord* block_start(const void* addr) const = 0;
 
-  // Requires "addr" to be the start of a chunk, and returns its size.
-  // "addr + size" is required to be the start of a new chunk, or the end
-  // of the active area of the heap.
-  virtual size_t block_size(const HeapWord* addr) const = 0;
-
   // Requires "addr" to be the start of a block, and returns "TRUE" iff
   // the block is an object.
   virtual bool block_is_obj(const HeapWord* addr) const = 0;