Handle Security Key requests from outside the remoted session correctly

remoting/host/security_key/security_key_message_handler.h

Index: remoting/host/security_key/security_key_message_handler.h
diff --git a/remoting/host/security_key/security_key_message_handler.h b/remoting/host/security_key/security_key_message_handler.h
index c14d393f85b18b32114af1c6ba9e0ccd422b93ea..8df9bb3af576a5d40f504811027c1aaea20c1d19 100644
--- a/remoting/host/security_key/security_key_message_handler.h
+++ b/remoting/host/security_key/security_key_message_handler.h
@@ -58,6 +58,9 @@ class SecurityKeyMessageHandler {
   // Used to respond to IPC connection changes.
   void HandleIpcConnectionChange(bool connection_established);
 
+  // Used to indicate an IPC connection error has occurred.
+  void HandleIpcConnectionError();
+
   // Handles responses received from the client.
   void HandleSecurityKeyResponse(const std::string& response_data);
 
@@ -79,6 +82,10 @@ class SecurityKeyMessageHandler {
   // Signaled when an error occurs.
   base::Closure error_callback_;
 
+  // Used to indicate when we expect the IPC channel to be closed (i.e. in the
+  // invalid session scenario) and when it is an unexpected error.
+  bool expect_ipc_channel_close_ = false;
+
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SecurityKeyMessageHandler);