Add support for jemalloc instead of dlmalloc.

Bug: 981363
Change-Id: I226ce3249c0d982eb1a9fdb9d04b25737f77345d
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index 7136c67..8c8a355 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -4039,7 +4039,11 @@
   // Send a series of heap segment chunks.
   HeapChunkContext context((what == HPSG_WHAT_MERGED_OBJECTS), native);
   if (native) {
+#ifdef USE_DLMALLOC
     dlmalloc_inspect_all(HeapChunkContext::HeapChunkCallback, &context);
+#else
+    UNIMPLEMENTED(WARNING) << "Native heap inspection is only supported with dlmalloc";
+#endif
   } else {
     gc::Heap* heap = Runtime::Current()->GetHeap();
     const std::vector<gc::space::ContinuousSpace*>& spaces = heap->GetContinuousSpaces();