Convert crypto to std::unique_ptr

crypto/hkdf.cc

Index: crypto/hkdf.cc
diff --git a/crypto/hkdf.cc b/crypto/hkdf.cc
index 67c39216b9653e535c7176a2eb9cc9faa6c22649..2483e6029bc0454fcf6fe3aead6e3aaa83bb13b4 100644
--- a/crypto/hkdf.cc
+++ b/crypto/hkdf.cc
@@ -7,8 +7,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include <memory>
+
 #include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
 #include "crypto/hmac.h"
 
 namespace crypto {
@@ -55,7 +56,7 @@ HKDF::HKDF(const base::StringPiece& secret,
   output_.resize(n * kSHA256HashLength);
   base::StringPiece previous;
 
-  scoped_ptr<char[]> buf(new char[kSHA256HashLength + info.size() + 1]);
+  std::unique_ptr<char[]> buf(new char[kSHA256HashLength + info.size() + 1]);
   uint8_t digest[kSHA256HashLength];
 
   HMAC hmac(HMAC::SHA256);