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/runtime/mem_map.cc b/runtime/mem_map.cc
index ffafc85..8a555fb 100644
--- a/runtime/mem_map.cc
+++ b/runtime/mem_map.cc
@@ -18,8 +18,8 @@
 
 #include <inttypes.h>
 #include <backtrace/BacktraceMap.h>
+#include <memory>
 
-#include "UniquePtrCompat.h"
 #include "base/stringprintf.h"
 #include "ScopedFd.h"
 #include "utils.h"
@@ -76,7 +76,7 @@
   uintptr_t expected = reinterpret_cast<uintptr_t>(expected_ptr);
   uintptr_t limit = expected + byte_count;
 
-  UniquePtr<BacktraceMap> map(BacktraceMap::Create(getpid()));
+  std::unique_ptr<BacktraceMap> map(BacktraceMap::Create(getpid()));
   if (!map->Build()) {
     *error_msg << StringPrintf("Failed to build process map to determine why mmap returned "
                                "0x%08" PRIxPTR " instead of 0x%08" PRIxPTR, actual, expected);