[Draft] Fix canceling pin prompt causes host overload

remoting/protocol/authenticator.h

Index: remoting/protocol/authenticator.h
diff --git a/remoting/protocol/authenticator.h b/remoting/protocol/authenticator.h
index 28288e59d448423f8ac304ee73bb17d59b956107..12109892472375e11291079646101cdd45190ddc 100644
--- a/remoting/protocol/authenticator.h
+++ b/remoting/protocol/authenticator.h
@@ -89,6 +89,11 @@ class Authenticator {
   // Returns current state of the authenticator.
   virtual State state() const = 0;
 
+  // Returns whether authentication has started. The chromoting host uses this
+  // method to starts the back off process to prevent malicious clients from
+  // guessing the PIN by spamming the host with auth requests.
+  virtual bool started() const = 0;
+
   // Returns rejection reason. Can be called only when in REJECTED state.
   virtual RejectionReason rejection_reason() const = 0;