Bootstrapping: Send meaningful error code/message from Slave to Master

components/pairing/host_pairing_controller.h

Index: components/pairing/host_pairing_controller.h
diff --git a/components/pairing/host_pairing_controller.h b/components/pairing/host_pairing_controller.h
index 76fdd66e7466bb735437e463a6ce04eef48d3a19..4e6b6122c4ccba17c239da11ce5c816ae5abb8ae 100644
--- a/components/pairing/host_pairing_controller.h
+++ b/components/pairing/host_pairing_controller.h
@@ -51,6 +51,14 @@ class HostPairingController {
     ENROLLMENT_STATUS_SUCCESS,
   };
 
+  enum class ErrorCode : int {
+    ERROR_NONE = 0,
+    NETWORK_ERROR,
+    AUTH_ERROR,
+    ENROLL_ERROR,
+    OTHER_ERROR,
+  };
+
   class Observer {
    public:
     Observer();
@@ -115,6 +123,9 @@ class HostPairingController {
   // Set the permanent id assigned during enrollment.
   virtual void SetPermanentId(const std::string& permanent_id) = 0;
 
+  virtual void SetErrorCodeAndMessage(int error_code,
+                                      const std::string& error_message) = 0;
+
   // Reset the controller.
   virtual void Reset() = 0;