libservo: Flesh out permissions API (#35396)

- Update the script crate to better reflect the modern Permission
  specifcation -- removing the necessity for an `Insecure` variant of
  the permissions prompt.
- Have all allow/deny type requests in the internal API use an
  `AllowOrDeny` enum for clarity.
- Expose `PermissionsRequest` and `PermissionFeature` data types to the
  API and use them in the delegate method.
- Update both servoshell implementations to use the API.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>

components/devtools/lib.rs

@@ -26,7 +26,7 @@ use devtools_traits::{
     DevtoolsControlMsg, DevtoolsPageInfo, LogLevel, NavigationState, NetworkEvent, PageError,
     ScriptToDevtoolsControlMsg, WorkerId,
 };
-use embedder_traits::{EmbedderMsg, EmbedderProxy};
+use embedder_traits::{AllowOrDeny, EmbedderMsg, EmbedderProxy};
 use ipc_channel::ipc::{self, IpcSender};
 use log::{debug, trace, warn};
 use serde::Serialize;
@@ -764,5 +764,5 @@ fn allow_devtools_client(stream: &mut TcpStream, embedder: &EmbedderProxy, token
     // No token found. Prompt user
     let (request_sender, request_receiver) = ipc::channel().expect("Failed to create IPC channel!");
     embedder.send(EmbedderMsg::RequestDevtoolsConnection(request_sender));
-    request_receiver.recv().unwrap()
+    request_receiver.recv().unwrap() == AllowOrDeny::Allow
 }