Revert scoped_types.h change.

This reverts commits:
8d79ed67407e433d80ebc8d3aa080e8ce16e6eb7
19fdcb523402ed13ab798cf811fb0119e3e7b104
8d79ed67407e433d80ebc8d3aa080e8ce16e6eb7

Because WebRTC (at least) includes our headers in an extern "C" block,
which precludes having any C++ in them.

Change-Id: Ia849f43795a40034cbd45b22ea680b51aab28b2d
diff --git a/crypto/bio/bio_test.cc b/crypto/bio/bio_test.cc
index cd56e62..e7c061e 100644
--- a/crypto/bio/bio_test.cc
+++ b/crypto/bio/bio_test.cc
@@ -40,6 +40,8 @@
 
 #include <algorithm>
 
+#include "../test/scoped_types.h"
+
 
 namespace bssl {