Add a mojo ServiceRegistry to embedded workers.

content/browser/service_worker/embedded_worker_instance.cc

Index: content/browser/service_worker/embedded_worker_instance.cc
diff --git a/content/browser/service_worker/embedded_worker_instance.cc b/content/browser/service_worker/embedded_worker_instance.cc
index 64f122f45e5c4f489abb264814848b27414de1b2..9866014e2e905319a41b8e3e26cd31b874d107c8 100644
--- a/content/browser/service_worker/embedded_worker_instance.cc
+++ b/content/browser/service_worker/embedded_worker_instance.cc
@@ -15,7 +15,9 @@
 #include "content/browser/service_worker/embedded_worker_registry.h"
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/common/content_switches_internal.h"
+#include "content/common/mojo/service_registry_impl.h"
 #include "content/common/service_worker/embedded_worker_messages.h"
+#include "content/common/service_worker/embedded_worker_setup.mojom.h"
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
@@ -83,6 +85,20 @@ void RegisterToWorkerDevToolsManagerOnUI(
       base::Bind(callback, worker_devtools_agent_route_id, wait_for_debugger));
 }
 
+void SetupMojoOnUIThread(int process_id,
+                         int thread_id,
+                         mojo::InterfaceRequest<mojo::ServiceProvider> services,
+                         mojo::ServiceProviderPtr exposed_services) {
+  RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
+  // |rph| may be NULL in unit tests.
+  if (!rph)
+    return;
+  EmbeddedWorkerSetupPtr setup;
+  rph->GetServiceRegistry()->ConnectToRemoteService(mojo::GetProxy(&setup));
+  setup->ExchangeServiceProviders(thread_id, services.Pass(),
+                                  exposed_services.Pass());
+}
+
 }  // namespace
 
 // Lives on IO thread, proxies notifications to DevToolsManager that lives on
@@ -202,6 +218,10 @@ ServiceWorkerStatusCode EmbeddedWorkerInstance::SendMessage(
                              thread_id_, embedded_worker_id_, message));
 }
 
+ServiceRegistry* EmbeddedWorkerInstance::GetServiceRegistry() {

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

Maybe DCHECK its either STARTING or RUNNING and service_registry_ is not null.

But as coded, I think that DCHECK would trip? The EmbeddedWorkerInstance goes
into the STARTING state in the Start() method, a whole lot happens prior to
OnScriptLoaded() running which is where the ServiceRegistry is being created.

Is it possible to create it and BindRemoteServiceProvider() here, and defer
SetupMojoOnUIThread until after the script has loaded? Or maybe just say "please
only call GetServiceRegistry() when its RUNNING."?

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

I added the DCHECK and moved the creating of the service_registry_ to the
Start() method. ServiceRegistry will just queue up any connection attempts until
it is bound to a remote service provider, so trying to use it before
SetupMojoOnUIThread is called works in that calls will eventually resolve
(assuming the worker actually starts). Creating the ServiceRegistry on demand
here in the getter would of course also work, but since it's always going to be
created anyway (and is fairly lightweight) I don't think that really gains us
much.

+  return service_registry_.get();
+}
+
 EmbeddedWorkerInstance::EmbeddedWorkerInstance(
     base::WeakPtr<ServiceWorkerContextCore> context,
     int embedded_worker_id)
@@ -344,6 +364,19 @@ void EmbeddedWorkerInstance::OnScriptLoaded(int thread_id) {
   }
   thread_id_ = thread_id;
   FOR_EACH_OBSERVER(Listener, listener_list_, OnScriptLoaded());
+
+  service_registry_.reset(new ServiceRegistryImpl());
+  mojo::ServiceProviderPtr exposed_services;
+  service_registry_->Bind(GetProxy(&exposed_services));
+  mojo::ServiceProviderPtr services;
+  mojo::InterfaceRequest<mojo::ServiceProvider> services_request =
+      GetProxy(&services);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(SetupMojoOnUIThread, process_id_, thread_id_,
+                 base::Passed(&services_request),
+                 base::Passed(&exposed_services)));
+  service_registry_->BindRemoteServiceProvider(services.Pass());
 }
 
 void EmbeddedWorkerInstance::OnScriptLoadFailed() {
@@ -376,6 +409,7 @@ void EmbeddedWorkerInstance::OnStarted() {
 void EmbeddedWorkerInstance::OnStopped() {
   Status old_status = status_;
   ReleaseProcess();
+  service_registry_.reset();
   FOR_EACH_OBSERVER(Listener, listener_list_, OnStopped(old_status));
 }