[proof-of-concept] SW thread independent of the main thread

content/browser/service_worker/service_worker_fetch_dispatcher.cc

Index: content/browser/service_worker/service_worker_fetch_dispatcher.cc
diff --git a/content/browser/service_worker/service_worker_fetch_dispatcher.cc b/content/browser/service_worker/service_worker_fetch_dispatcher.cc
index 4e5329846dab76906d6c26df860526206309182b..7e8da3ab82d1c5ea0df7d5be3bfdb44c9d5c2976 100644
--- a/content/browser/service_worker/service_worker_fetch_dispatcher.cc
+++ b/content/browser/service_worker/service_worker_fetch_dispatcher.cc
@@ -117,6 +117,8 @@ ServiceWorkerFetchDispatcher::ServiceWorkerFetchDispatcher(
       resource_type_(resource_type),
       did_complete_(false),
       weak_factory_(this) {
+  LOG(ERROR) << "ServiceWorkerFetchDispatcher::ServiceWorkerFetchDispatcher "
+             << this;
   net_log_.BeginEvent(net::NetLog::TYPE_SERVICE_WORKER_DISPATCH_FETCH_EVENT,
                       net::NetLog::StringCallback(
                           "event_type", ServiceWorkerMetrics::EventTypeToString(
@@ -124,6 +126,8 @@ ServiceWorkerFetchDispatcher::ServiceWorkerFetchDispatcher(
 }
 
 ServiceWorkerFetchDispatcher::~ServiceWorkerFetchDispatcher() {
+  LOG(ERROR) << "ServiceWorkerFetchDispatcher::~ServiceWorkerFetchDispatcher "
+             << this;
   if (!did_complete_)
     net_log_.EndEvent(net::NetLog::TYPE_SERVICE_WORKER_DISPATCH_FETCH_EVENT);
 }
@@ -183,6 +187,7 @@ void ServiceWorkerFetchDispatcher::DidFailToStartWorker(
 }
 
 void ServiceWorkerFetchDispatcher::DispatchFetchEvent() {
+  LOG(ERROR) << "ServiceWorkerFetchDispatcher::DispatchFetchEvent";
   DCHECK_EQ(EmbeddedWorkerStatus::RUNNING, version_->running_status())
       << "Worker stopped too soon after it was started.";
 
@@ -191,6 +196,23 @@ void ServiceWorkerFetchDispatcher::DispatchFetchEvent() {
   prepare_callback.Run();
 
   net_log_.BeginEvent(net::NetLog::TYPE_SERVICE_WORKER_FETCH_EVENT);
+
+  if (version_->IsIsolatedWorker()) {
+    int response_id = version_->StartRequest(
+        GetEventType(),
+        base::Bind(&ServiceWorkerFetchDispatcher::DidFailToDispatch,
+                   weak_factory_.GetWeakPtr()));
+    int event_finish_id = version_->StartRequest(
+        FetchTypeToWaitUntilEventType(request_->fetch_type),
+        base::Bind(&ServiceWorkerUtils::NoOpStatusCallback));
+    version_->isolated_worker_ptr()->OnFetchEvent(
+        response_id, event_finish_id, request_->url.spec(),
+        request_->mode == FETCH_REQUEST_MODE_NAVIGATE,
+        base::Bind(&ServiceWorkerFetchDispatcher::OnFetchEventCallback,
+                   weak_factory_.GetWeakPtr()));
+    return;
+  }
+
   int response_id = version_->StartRequest(
       GetEventType(),
       base::Bind(&ServiceWorkerFetchDispatcher::DidFailToDispatch,
@@ -233,6 +255,33 @@ void ServiceWorkerFetchDispatcher::DidFinish(
   Complete(SERVICE_WORKER_OK, fetch_result, response);
 }
 
+void ServiceWorkerFetchDispatcher::OnFetchEventCallback(
+    bool handled,
+    mojo::StructPtr<blink::mojom::ServiceWorkerResponse> response) {
+  LOG(ERROR) << "ServiceWorkerFetchDispatcher::OnFetchEventCallback "
+             << handled;
+  net_log_.EndEvent(net::NetLog::TYPE_SERVICE_WORKER_FETCH_EVENT);
+  ServiceWorkerResponse result;
+  if (response) {
+    LOG(ERROR) << " url: " << response->url;
+    LOG(ERROR) << " status_code: " << response->status_code;
+    LOG(ERROR) << " status_text: " << response->status_text;
+    LOG(ERROR) << " blob_uuid: " << response->blob_uuid;
+    LOG(ERROR) << " blob_size: " << response->blob_size;
+    LOG(ERROR) << " stream_url: " << response->stream_url;
+    result.url = GURL(std::string(response->url));
+    result.status_code = response->status_code;
+    result.status_text = response->status_text;
+    result.blob_uuid = response->blob_uuid;
+    result.blob_size = response->blob_size;
+    result.stream_url = GURL(std::string(response->stream_url));
+  }
+  Complete(SERVICE_WORKER_OK,
+           handled ? SERVICE_WORKER_FETCH_EVENT_RESULT_RESPONSE
+                   : SERVICE_WORKER_FETCH_EVENT_RESULT_FALLBACK,
+           result);
+}
+
 void ServiceWorkerFetchDispatcher::Complete(
     ServiceWorkerStatusCode status,
     ServiceWorkerFetchEventResult fetch_result,