Revert "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 c7fac32149dee12aa482657a72ffebe954546add..b47f556b5b51924ddf4fa340799cb22980e6c55d 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -201,21 +201,6 @@ void OnEventDispatcherConnectionError(
   }
 }
 
-mojom::ServiceWorkerProviderInfoForStartWorkerPtr
-CompleteProviderHostPreparation(
-    ServiceWorkerVersion* version,
-    std::unique_ptr<ServiceWorkerProviderHost> provider_host,
-    base::WeakPtr<ServiceWorkerContextCore> context,
-    int process_id) {
-  // Caller should ensure |context| is alive when completing StartWorker
-  // preparation.
-  DCHECK(context);
-  auto info =
-      provider_host->CompleteStartWorkerPreparation(process_id, version);
-  context->AddProviderHost(std::move(provider_host));
-  return info;
-}
-
 }  // namespace
 
 constexpr base::TimeDelta ServiceWorkerVersion::kTimeoutTimerDelay;
@@ -855,9 +840,6 @@ 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();
 }
@@ -1476,10 +1458,6 @@ void ServiceWorkerVersion::StartWorkerInternal() {
 
   StartTimeoutTimer();
 
-  std::unique_ptr<ServiceWorkerProviderHost> pending_provider_host =
-      ServiceWorkerProviderHost::PreCreateForController(context());
-  provider_host_ = pending_provider_host->AsWeakPtr();
-
   auto params = base::MakeUnique<EmbeddedWorkerStartParams>();
   params->service_worker_version_id = version_id_;
   params->scope = scope_;
@@ -1488,12 +1466,7 @@ void ServiceWorkerVersion::StartWorkerInternal() {
   params->pause_after_download = pause_after_download_;
 
   embedded_worker_->Start(
-      std::move(params),
-      // Unretained is used here because the callback will be owned by
-      // |embedded_worker_| whose owner is |this|.
-      base::BindOnce(&CompleteProviderHostPreparation, base::Unretained(this),
-                     base::Passed(&pending_provider_host), context()),
-      mojo::MakeRequest(&event_dispatcher_),
+      std::move(params), mojo::MakeRequest(&event_dispatcher_),
       base::Bind(&ServiceWorkerVersion::OnStartSentAndScriptEvaluated,
                  weak_factory_.GetWeakPtr()));
   event_dispatcher_.set_connection_error_handler(base::Bind(