Remove unused member function from art::Heap.

Change-Id: I3f5417745cd7a3453bbbbd5159a5da79b2d44a16
diff --git a/src/heap.h b/src/heap.h
index b91868c..75362ce 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -254,7 +254,6 @@
   void RequestConcurrentGC();
 
   void RecordAllocationLocked(AllocSpace* space, const Object* object);
-  void RecordImageAllocations(Space* space);
 
   // TODO: can we teach GCC to understand the weird locking in here?
   void CollectGarbageInternal(bool concurrent, bool clear_soft_references) NO_THREAD_SAFETY_ANALYSIS;