Make RemoteSettingsClient::get_attachment input a reference

This won't change anything when it's called from UniFFI since we still
need to copy the data to pass it over the FFI.  However, we're starting
to use this client internally as well and this makes it so we can avoid
a copy when calling the method from Rust.

Author: bendk

components/remote_settings/src/client.rs

@@ -372,9 +372,10 @@ impl<C: ApiClient> RemoteSettingsClient<C> {
 
     /// Downloads an attachment from [attachment_location]. NOTE: there are no guarantees about a
     /// maximum size, so use care when fetching potentially large attachments.
-    pub fn get_attachment(&self, record: RemoteSettingsRecord) -> Result<Vec<u8>> {
+    pub fn get_attachment(&self, record: &RemoteSettingsRecord) -> Result<Vec<u8>> {
         let metadata = record
             .attachment
+            .as_ref()
             .ok_or_else(|| Error::RecordAttachmentMismatchError("No attachment metadata".into()))?;
 
         let mut inner = self.inner.lock();
@@ -2427,7 +2428,7 @@ mod test_packaged_metadata {
             fields: serde_json::json!({}).as_object().unwrap().clone(),
         };
 
-        let attachment_data = rs_client.get_attachment(record)?;
+        let attachment_data = rs_client.get_attachment(&record)?;
 
         // Verify we got the expected data
         let expected_data = std::fs::read(file_path)?;
@@ -2483,7 +2484,7 @@ mod test_packaged_metadata {
             fields: serde_json::json!({}).as_object().unwrap().clone(),
         };
 
-        let attachment_data = rs_client.get_attachment(record)?;
+        let attachment_data = rs_client.get_attachment(&record)?;
 
         // Verify we got the mock API data, not the packaged data
         assert_eq!(attachment_data, vec![1, 2, 3, 4, 5]);

components/remote_settings/src/lib.rs

@@ -196,7 +196,7 @@ impl RemoteSettingsClient {
     ///   - This method will throw if there is a network or other error when fetching the
     ///     attachment data.
     #[handle_error(Error)]
-    pub fn get_attachment(&self, record: RemoteSettingsRecord) -> ApiResult<Vec<u8>> {
+    pub fn get_attachment(&self, record: &RemoteSettingsRecord) -> ApiResult<Vec<u8>> {
         self.internal.get_attachment(record)
     }
 }