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..073f29da41126b352bfb80af3f6c3a039e2e1291 100644
--- a/components/client_update_protocol/ecdsa.h
+++ b/components/client_update_protocol/ecdsa.h
@@ -13,6 +13,12 @@
 
 #include "base/strings/string_piece.h"
 
+// Testing peers. There's a better way to do this, but it probably makes sense
+// to wait til there are one or two more.
+namespace network_time {
+class NetworkTimeTrackerTest;
+}  // namespace network_time
+
 namespace client_update_protocol {
 
 // Client Update Protocol v2, or CUP-ECDSA, is used by Google Update (Omaha)
@@ -51,15 +57,16 @@ 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;
+  friend class network_time::NetworkTimeTrackerTest;

[Ryan Sleevi, 2016/04/29 22:54:15]

FWIW, this feels like a layering violation (//components/client_update_protocol
sets below //components/network_time/, so CUP shouldn't know about network_time,
nor should network_time be reaching in to the implementation rather than the
interface).

The alternative way to do this would be something like OverrideKeyForTesting()
or something (as a public method), which our presubmit code would enforce is
only used in _unittest files. Whether that's strictly better is subjective - it
leaks more of the interface out, such that anyone can use it, but keeps the
dependencies better aligned. Just $.02

[mab, 2016/04/29 23:30:08]

I didn't know the |ForTesting| suffix was enforced.  That does change the
balance.  Done.

waffles, you OK with this?

[waffles, 2016/04/30 00:03:36]

I'm OK with it. I'll admit it seems a little bit weird to me.

 
   Ecdsa(int key_version, const base::StringPiece& public_key);