Backed out changeset 706e9934d689 (bug 1888472) for causing build bustages @ Cargo.lock CLOSED TREE

docs/writing-rust-code/xpcom.md

@@ -111,3 +111,10 @@ The following XPCOM components are written in Rust.
   which [merges](https://mozilla.github.io/dogear) bookmarks from Firefox Sync
   with bookmarks in the Places database.
   [There's also some docs on how Rust interacts with Sync](/services/sync/rust-engines.rst)
+- [webext_storage_bridge](https://searchfox.org/mozilla-central/source/toolkit/components/extensions/storage/webext_storage_bridge),
+  which powers the WebExtension storage.sync API. It's a self-contained example
+  that pulls in a crate from application-services for the heavy lifting, wraps
+  that up in a Rust XPCOM component, and then wraps the component in a JS
+  interface. There's also some boilerplate there around adding a
+  `components.conf` file, and a dummy C++ header that declares the component
+  constructor. [It has some in-depth documentation on how it hangs together](../toolkit/components/extensions/webextensions/webext-storage.rst).