Put FontFace constructor to Immutable slice whitelist (#3072)

* Put FontFace constructor to Immutable slice whitelist

* Update gen_FontFace.rs

crates/web-sys/src/features/gen_FontFace.rs

@@ -185,7 +185,7 @@ extern "C" {
     #[doc = "[MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/API/FontFace/FontFace)"]
     #[doc = ""]
     #[doc = "*This API requires the following crate features to be activated: `FontFace`*"]
-    pub fn new_with_u8_array(family: &str, source: &mut [u8]) -> Result<FontFace, JsValue>;
+    pub fn new_with_u8_array(family: &str, source: &[u8]) -> Result<FontFace, JsValue>;
     #[cfg(feature = "FontFaceDescriptors")]
     #[wasm_bindgen(catch, constructor, js_class = "FontFace")]
     #[doc = "The `new FontFace(..)` constructor, creating a new instance of `FontFace`."]
@@ -231,7 +231,7 @@ extern "C" {
     #[doc = "*This API requires the following crate features to be activated: `FontFace`, `FontFaceDescriptors`*"]
     pub fn new_with_u8_array_and_descriptors(
         family: &str,
-        source: &mut [u8],
+        source: &[u8],
         descriptors: &FontFaceDescriptors,
     ) -> Result<FontFace, JsValue>;
     # [wasm_bindgen (catch , method , structural , js_class = "FontFace" , js_name = load)]

crates/webidl/src/constants.rs

@@ -87,6 +87,8 @@ pub(crate) static IMMUTABLE_SLICE_WHITELIST: Lazy<BTreeSet<&'static str>> = Lazy
         "writeBuffer",
         "writeTexture",
         // AudioBuffer
-        "copyToChannel", // TODO: Add another type's functions here. Leave a comment header with the type name
+        "copyToChannel",
+        // FontFace
+        "FontFace", // TODO: Add another type's functions here. Leave a comment header with the type name
     ])
 });