Mandoline: Implement basic "process per site" support

mojo/services/network/public/interfaces/network_service.mojom

Index: mojo/services/network/public/interfaces/network_service.mojom
diff --git a/mojo/services/network/public/interfaces/network_service.mojom b/mojo/services/network/public/interfaces/network_service.mojom
index 1f67253fe482b3a0843c4fd22469c7bee09065d9..e532b2f5c3657a4261b121a134f1501a029a54a1 100644
--- a/mojo/services/network/public/interfaces/network_service.mojom
+++ b/mojo/services/network/public/interfaces/network_service.mojom
@@ -19,6 +19,8 @@ import "network/public/interfaces/web_socket.mojom";
 interface NetworkService {
   GetCookieStore(CookieStore& cookie_store);
 
+  GetSiteForURL(string url) => (string site);
+
   CreateWebSocket(WebSocket& socket);
 
   // Creates a TCP socket bound to a given local address. This bound socket
@@ -69,4 +71,6 @@ interface NetworkService {
                    HttpServerDelegate delegate)
       => (NetworkError result,
           NetAddress? bound_to);
+
+
 };