Add a mojo ServiceRegistry to embedded workers.

content/renderer/service_worker/service_worker_context_client.cc

Index: content/renderer/service_worker/service_worker_context_client.cc
diff --git a/content/renderer/service_worker/service_worker_context_client.cc b/content/renderer/service_worker/service_worker_context_client.cc
index aad3c7210dc7959a38026c7159e5a587cfdaef46..2efc2fa6dfecf33e8565dfc1418b37d98699ceb8 100644
--- a/content/renderer/service_worker/service_worker_context_client.cc
+++ b/content/renderer/service_worker/service_worker_context_client.cc
@@ -271,6 +271,13 @@ void ServiceWorkerContextClient::OnMessageReceived(
   DCHECK(handled);
 }
 
+void ServiceWorkerContextClient::BindServiceRegistry(
+    mojo::InterfaceRequest<mojo::ServiceProvider> services,
+    mojo::ServiceProviderPtr exposed_services) {
+  service_registry_.Bind(services.Pass());
+  service_registry_.BindRemoteServiceProvider(exposed_services.Pass());

[michaeln, 2015/07/15 02:34:22]

Script will be running before this happens. Does that have an impact on whether
this registry pair can be used as an ipc replacement for worker to browser
messaging. Suppose during eval, script calls a method back by c++. Can it use
the registry prior to the Bind happening?

[Marijn Kruisselbrink, 2015/07/15 18:13:28]

The service registry is usable before either Bind happens. Attempts to connect
to remote services are just queued up until BindRemoteServiceProvider is
eventually called (or until the registry is destroyed if
BindRemoteServiceProvider was never called).

[michaeln, 2015/07/15 21:18:51]

thats neat

+}
+
 blink::WebURL ServiceWorkerContextClient::scope() const {
   return service_worker_scope_;
 }