Do they really need to access thousands of C++ API calls from Rust? Doesn't this defeat the purpose of writing safe code in Rust? This smells of "not invented here" which applies to Google projects pretty often.

They should focus on integrating Rust in portions of the API instead of exposing a gigantic unsafe API surface, essentially making all their code unsafe. Unless the Chrome codebase is really such a mess that they can't do anything without exposing this giant API surface. In that case they should rewrite it to... not do that.

"We can't use Rust unless it allows us to write all our code in C++ without showing unsafe warnings"