Remove direct dependence on stlport

Change-Id: I17caa47ff8b4a38d7015ac0509789c5475f23e21
diff --git a/include/nativehelper/UniquePtr.h b/include/nativehelper/UniquePtr.h
index e27e941..50f75b2 100644
--- a/include/nativehelper/UniquePtr.h
+++ b/include/nativehelper/UniquePtr.h
@@ -17,9 +17,13 @@
 #ifndef UNIQUE_PTR_H_included
 #define UNIQUE_PTR_H_included
 
-#include <algorithm> // For std::swap
 #include <cstdlib> // For NULL.
 
+// This is a fake declaration of std::swap to avoid including <algorithm>
+namespace std {
+template <class T> void swap(T&, T&);
+}
+
 // Default deleter for pointer types.
 template <typename T>
 struct DefaultDelete {