Use base::Clock in AuthManager for better testing

Change-Id: Ifbb23e4da565a1c86ff728803d2e07e3f8c3b1f4
Reviewed-on: https://weave-review.googlesource.com/1873
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/src/privet/security_delegate.h b/src/privet/security_delegate.h
index 40f297f..051bf20 100644
--- a/src/privet/security_delegate.h
+++ b/src/privet/security_delegate.h
@@ -22,8 +22,7 @@
   virtual ~SecurityDelegate() {}
 
   // Creates access token for the given scope, user id and |time|.
-  virtual std::string CreateAccessToken(const UserInfo& user_info,
-                                        const base::Time& time) = 0;
+  virtual std::string CreateAccessToken(const UserInfo& user_info) = 0;
 
   // Validates |token| and returns scope and user id parsed from that.
   virtual UserInfo ParseAccessToken(const std::string& token,