Add support for crypto::ECPrivateKey::Copy when built with BoringSSL

crypto/ec_private_key.h

Index: crypto/ec_private_key.h
diff --git a/crypto/ec_private_key.h b/crypto/ec_private_key.h
index a3d3d1ea02ac33ad9243e62cf9965cdc0a90c1c8..87af838904ae63b09e472f74ee25cd3aaa814b76 100644
--- a/crypto/ec_private_key.h
+++ b/crypto/ec_private_key.h
@@ -66,10 +66,10 @@ class CRYPTO_EXPORT ECPrivateKey {
       bool sensitive,
       SECKEYPrivateKey** key,
       SECKEYPublicKey** public_key);
+#endif
 
   // Returns a copy of the object.
   ECPrivateKey* Copy() const;
-#endif
 
 #if defined(USE_OPENSSL)
   EVP_PKEY* key() { return key_; }