Create ServiceWorkerProviderHost before starting worker

content/browser/service_worker/service_worker_version.cc

Index: content/browser/service_worker/service_worker_version.cc
diff --git a/content/browser/service_worker/service_worker_version.cc b/content/browser/service_worker/service_worker_version.cc
index 59ece4dc11d2a0ed82e3d4228459c3b969649061..90093274de58307c99d35eb946c5d61ea0268e43 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -827,6 +827,9 @@ ServiceWorkerVersion::PendingRequest::~PendingRequest() {}
 
 void ServiceWorkerVersion::OnThreadStarted() {
   DCHECK_EQ(EmbeddedWorkerStatus::STARTING, running_status());
+  DCHECK(provider_host_);
+  provider_host_->SetReadyToSendMessagesToWorker(
+      embedded_worker()->thread_id());
   // Activate ping/pong now that JavaScript execution will start.
   ping_controller_->Activate();
 }
@@ -836,6 +839,11 @@ void ServiceWorkerVersion::OnStarting() {
     observer.OnRunningStateChanged(this);
 }
 
+void ServiceWorkerVersion::OnStartWorkerMessageSent() {
+  DCHECK(pending_provider_host_);
+  context()->AddProviderHost(std::move(pending_provider_host_));
+}
+
 void ServiceWorkerVersion::OnStarted() {
   DCHECK_EQ(EmbeddedWorkerStatus::RUNNING, running_status());
   RestartTick(&idle_time_);
@@ -1428,12 +1436,18 @@ void ServiceWorkerVersion::StartWorkerInternal() {
 
   StartTimeoutTimer();
 
+  DCHECK(!pending_provider_host_);
+  pending_provider_host_ =
+      ServiceWorkerProviderHost::PreCreateForWorkerContext(this, context());
+  provider_host_ = pending_provider_host_->AsWeakPtr();
+
   auto params = base::MakeUnique<EmbeddedWorkerStartParams>();
   params->service_worker_version_id = version_id_;
   params->scope = scope_;
   params->script_url = script_url_;
   params->is_installed = IsInstalled(status_);
   params->pause_after_download = pause_after_download_;
+  params->controller_provider = pending_provider_host_.get();
 
   embedded_worker_->Start(
       std::move(params), mojo::MakeRequest(&event_dispatcher_),