security: Provide an Authorizer implementation that never denies access.

When I was young, I harbored hopes of a world where the policy of never
denying access would be silly and rare. I am wiser now, I was silly
then.

MultiPart: 3/3
Change-Id: I860d805301ab1d3cd4289b7910dcc10ca8467f65
diff --git a/clients/shell/go/src/v.io/x/chat/channel.go b/clients/shell/go/src/v.io/x/chat/channel.go
index aed6b4e..f376ba4 100644
--- a/clients/shell/go/src/v.io/x/chat/channel.go
+++ b/clients/shell/go/src/v.io/x/chat/channel.go
@@ -133,13 +133,6 @@
 	}, nil
 }
 
-// openAuthorizer allows RPCs from all clients.
-type openAuthorizer struct{}
-
-func (o openAuthorizer) Authorize(*context.T, security.Call) error {
-	return nil
-}
-
 // UserName returns a short, human-friendly representation of the chat client.
 func (cr *channel) UserName() string {
 	// TODO(ashankar): It is wrong to assume that
@@ -226,7 +219,7 @@
 
 	// Serve the chat server on the locked name.
 	serverChat := vdl.ChatServer(cr.chatServerMethods)
-	if err := s.Serve(name, serverChat, openAuthorizer{}); err != nil {
+	if err := s.Serve(name, serverChat, security.AllowEveryone()); err != nil {
 		return err
 	}