update_engine: Add minutes variable to real time provider.

Make it so that the user can also get the current
minutes in local time from the real time provider.

BUG=chromium:852860
TEST=Real time provider unittests
Change-Id: I8118e28c5ab7f000434947fdee9aeae441535ba6
Reviewed-on: https://chromium-review.googlesource.com/1101468
Commit-Ready: Adolfo Higueros <adokar@google.com>
Tested-by: Adolfo Higueros <adokar@google.com>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/update_manager/time_provider.h b/update_manager/time_provider.h
index 663ec2c..94f4a8f 100644
--- a/update_manager/time_provider.h
+++ b/update_manager/time_provider.h
@@ -36,6 +36,9 @@
   // consistent with base::Time.
   virtual Variable<int>* var_curr_hour() = 0;
 
+  // Returns the current minutes (0 to 60) in local time.
+  virtual Variable<int>* var_curr_minute() = 0;
+
  protected:
   TimeProvider() {}