--- old/src/share/vm/gc/shared/collectedHeap.cpp	2017-07-19 17:26:35.791457100 +0200
+++ new/src/share/vm/gc/shared/collectedHeap.cpp	2017-07-19 17:26:34.850951100 +0200
@@ -594,11 +594,12 @@
     HeapDumper::dump_heap();
   }
 
-  Log(gc, classhisto) log;
-  if (log.is_trace()) {
+  LogTarget(Trace, gc, classhisto) lt;
+  if (lt.is_enabled()) {
     GCTraceTime(Trace, gc, classhisto) tm(before ? "Class Histogram (before full gc)" : "Class Histogram (after full gc)", timer);
     ResourceMark rm;
-    VM_GC_HeapInspection inspector(log.trace_stream(), false /* ! full gc */);
+    LogStream ls(lt);
+    VM_GC_HeapInspection inspector(&ls, false /* ! full gc */);
     inspector.doit();
   }
 }