bufferstreams: Make BufferOwner Send+Sync
This is important for IPCs to work, since buffers can come in over the
wire, be processed by binder threads, and handed off to
client-controlled worker threads.
Bug: 296099728
Test: atest
Change-Id: I9c32ac17e07456aa6a8e7211c67893a51fc9724c
diff --git a/libs/bufferstreams/rust/src/buffers/buffer_owner.rs b/libs/bufferstreams/rust/src/buffers/buffer_owner.rs
index a4abb9d..155a8bf 100644
--- a/libs/bufferstreams/rust/src/buffers/buffer_owner.rs
+++ b/libs/bufferstreams/rust/src/buffers/buffer_owner.rs
@@ -16,7 +16,7 @@
/// Trait that represents an owner of a buffer that might need to handle events such as a buffer
/// being dropped.
-pub trait BufferOwner {
+pub trait BufferOwner: Send + Sync {
/// Called when a buffer is dropped.
fn on_return(&self, buffer: &Buffer);
}