Private API for extensions like ssh-client that need access to TCP.

base/hmac.h

Index: base/hmac.h
diff --git a/base/hmac.h b/base/hmac.h
index 259330782b2c4e3c611750d173e150c5d48d7a86..a19c99aaa1f693cd6a3d0e1a9680e3ad997915fe 100644
--- a/base/hmac.h
+++ b/base/hmac.h
@@ -45,7 +45,8 @@ class BASE_API HMAC {
   // Calculates the HMAC for the message in |data| using the algorithm supplied
   // to the constructor and the key supplied to the Init method. The HMAC is
   // returned in |digest|, which has |digest_length| bytes of storage available.
-  bool Sign(const std::string& data, unsigned char* digest, int digest_length);
+  bool Sign(
+      const std::string& data, unsigned char* digest, int digest_length) const;
 
   // TODO(albertb): Add a Verify method.