Create ServiceWorkerProviderHost before starting worker

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 3db1cf81460c105aa474848fddf55db0b01a57ca..6da46b55e41ab56c4097d54ea873ba563a7a0444 100644
--- a/content/renderer/service_worker/service_worker_context_client.cc
+++ b/content/renderer/service_worker/service_worker_context_client.cc
@@ -554,6 +554,7 @@ ServiceWorkerContextClient::ServiceWorkerContextClient(
     const GURL& script_url,
     mojom::ServiceWorkerEventDispatcherRequest dispatcher_request,
     mojom::EmbeddedWorkerInstanceHostAssociatedPtrInfo instance_host,
+    mojom::ServiceWorkerProviderClientInfoPtr provider_client_info,
     std::unique_ptr<EmbeddedWorkerInstanceClientImpl> embedded_worker_client)
     : embedded_worker_id_(embedded_worker_id),
       service_worker_version_id_(service_worker_version_id),
@@ -575,6 +576,11 @@ ServiceWorkerContextClient::ServiceWorkerContextClient(
       "ServiceWorkerContextClient::StartingWorkerContext",
       this,
       "PrepareWorker");
+  // Create a content::ServiceWorkerNetworkProvider for this data source so
+  // we can observe its requests.
+  pending_network_provider_ = base::MakeUnique<ServiceWorkerNetworkProvider>(
+      std::move(provider_client_info));
+  provider_context_ = pending_network_provider_->context();
 }
 
 ServiceWorkerContextClient::~ServiceWorkerContextClient() {}
@@ -709,9 +715,7 @@ void ServiceWorkerContextClient::WorkerContextStarted(
 
   SetRegistrationInServiceWorkerGlobalScope(registration_info, version_attrs);
 
-  (*instance_host_)
-      ->OnThreadStarted(WorkerThread::GetCurrentId(),
-                        provider_context_->provider_id());
+  (*instance_host_)->OnThreadStarted(WorkerThread::GetCurrentId());
 
   TRACE_EVENT_ASYNC_STEP_INTO0(
       "ServiceWorker",
@@ -1087,23 +1091,9 @@ void ServiceWorkerContextClient::DidHandlePaymentRequestEvent(
 std::unique_ptr<blink::WebServiceWorkerNetworkProvider>
 ServiceWorkerContextClient::CreateServiceWorkerNetworkProvider() {
   DCHECK(main_thread_task_runner_->RunsTasksInCurrentSequence());
-
-  // Create a content::ServiceWorkerNetworkProvider for this data source so
-  // we can observe its requests.
-  std::unique_ptr<ServiceWorkerNetworkProvider> provider =
-      base::MakeUnique<ServiceWorkerNetworkProvider>(
-          MSG_ROUTING_NONE, SERVICE_WORKER_PROVIDER_FOR_CONTROLLER,
-          true /* is_parent_frame_secure */);
-  provider_context_ = provider->context();
-  network_provider_id_ = provider->provider_id();
-
-  // Tell the network provider about which version to load.
-  provider->SetServiceWorkerVersionId(service_worker_version_id_,
-                                      embedded_worker_id_);
-
   // Blink is responsible for deleting the returned object.
   return base::MakeUnique<WebServiceWorkerNetworkProviderImpl>(
-      std::move(provider));
+      std::move(pending_network_provider_));

[xiaofengzhang, 2017/06/06 03:22:23]

I have a stupid question here:
CreateServiceWorkerNetworkProvider should be called in
WebEmbeddedWorkerImpl::DidFinishDocumentLoad which seems before the
StartWorker()?
But ServiceWorkerContextClient is constructed in StartWorker(), and
ServiceWorkerNetworkProvider is created in the constructor of
ServiceWorkerContextClient?

[shimazu, 2017/06/06 04:16:56]

It might be a complicated part of starting up. 
EmbeddedWorkerClientImpl::StartWorker creates and starts WebEmbeddedWorkerImpl,
and WebEmbeddedWorkerImpl internally prepares a frame called a "shadow page".
DidFinishDocumentLoad is called when WebEmbeddedWorkerImpl::LoadShadowPage is
finished, and it means the shadow page gets ready. The shadow page is used for
loading the worker's script; it's main_script_loader_->LoadAsynchronously(...)
on this link:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/web/WebEmbedde...
.

 }
 
 std::unique_ptr<blink::WebWorkerFetchContext>