Now we have a proper C++ library, use std::unique_ptr.

Also remove the Android.libcxx.mk and other bits of stlport compatibility
mechanics.

Change-Id: Icdf7188ba3c79cdf5617672c1cfd0a68ae596a61
diff --git a/test/ReferenceMap/stack_walk_refmap_jni.cc b/test/ReferenceMap/stack_walk_refmap_jni.cc
index d8a0eef..48a6c61 100644
--- a/test/ReferenceMap/stack_walk_refmap_jni.cc
+++ b/test/ReferenceMap/stack_walk_refmap_jni.cc
@@ -15,8 +15,8 @@
  */
 
 #include <stdio.h>
+#include <memory>
 
-#include "UniquePtrCompat.h"
 #include "class_linker.h"
 #include "dex_file-inl.h"
 #include "gc_map.h"