network_time_tracker: add temporary time protocol.

components/client_update_protocol/ecdsa.h

Index: components/client_update_protocol/ecdsa.h
diff --git a/components/client_update_protocol/ecdsa.h b/components/client_update_protocol/ecdsa.h
index 889a396e2b450ea5be827ff2d3797577ea6f663e..24e4171ba8e59c39060dec4d4a29121460189c18 100644
--- a/components/client_update_protocol/ecdsa.h
+++ b/components/client_update_protocol/ecdsa.h
@@ -51,16 +51,18 @@ class Ecdsa {
 
   // Validates a response given to a ping previously signed with
   // SignRequest(). |response_body| contains the body of the response in
-  // UTF-8. |server_proof| contains the ECDSA signature and observed request
-  // hash, which is passed in the ETag HTTP header. Returns true if the response
-  // is valid and the observed request hash matches the sent hash.  This method
-  // uses internal state that is set by a prior SignRequest() call.
+  // UTF-8. |signature| contains the ECDSA signature and observed request
+  // hash. Returns true if the response is valid and the observed request hash
+  // matches the sent hash.  This method uses internal state that is set by a
+  // prior SignRequest() call.
   bool ValidateResponse(const base::StringPiece& response_body,
-                        const base::StringPiece& server_etag);
+                        const base::StringPiece& signature);
 
- private:
-  friend class CupEcdsaTest;
+  // Sets the key and nonce that were used to generate a signature that is baked
+  // into a unit test.
+  void OverrideNonceForTesting(int key_version, uint32_t nonce);
 
+ private:
   Ecdsa(int key_version, const base::StringPiece& public_key);
 
   // The server keeps multiple signing keys; a version must be sent so that