CRYPTO - Resolved comments from wtc. Used scoped_ptr<char[]> and

crypto/hkdf.h

Index: crypto/hkdf.h
===================================================================
--- crypto/hkdf.h	(revision 184497)
+++ crypto/hkdf.h	(working copy)
@@ -35,7 +35,7 @@
        const base::StringPiece& info,
        size_t key_bytes_to_generate,
        size_t iv_bytes_to_generate);
-  virtual ~HKDF();
+  ~HKDF();
 
   base::StringPiece client_write_key() const {
     return client_write_key_;