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

content/browser/service_worker/service_worker_fetch_dispatcher.h

Index: content/browser/service_worker/service_worker_fetch_dispatcher.h
diff --git a/content/browser/service_worker/service_worker_fetch_dispatcher.h b/content/browser/service_worker/service_worker_fetch_dispatcher.h
index b1010c7aa9dbb111ac9e06e1f055c255efcaa879..02e456786c56c3eef92226468b8edd6c1629138f 100644
--- a/content/browser/service_worker/service_worker_fetch_dispatcher.h
+++ b/content/browser/service_worker/service_worker_fetch_dispatcher.h
@@ -14,7 +14,14 @@
 #include "content/common/service_worker/service_worker_types.h"
 #include "content/public/common/resource_type.h"
 #include "net/log/net_log.h"
+#include "mojo/public/cpp/bindings/string.h"
+#include "mojo/public/cpp/bindings/struct_ptr.h"
 
+namespace blink {
+namespace mojom {
+class ServiceWorkerResponse;
+}
+}
 namespace content {
 
 class ServiceWorkerVersion;
@@ -60,6 +67,10 @@ class CONTENT_EXPORT ServiceWorkerFetchDispatcher {
                 ServiceWorkerFetchEventResult fetch_result,
                 const ServiceWorkerResponse& response);
 
+  void OnFetchEventCallback(
+      bool handled,
+      mojo::StructPtr<blink::mojom::ServiceWorkerResponse> response);
+
   ServiceWorkerMetrics::EventType GetEventType() const;
 
   scoped_refptr<ServiceWorkerVersion> version_;