[Background Sync] Use Mojo IPC to fire background sync events

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 55b6a0e5dc2822ab51e846b8525fa0765b1a0f2f..91ec0988c8392947d5bfdc11883cde8078e1dff1 100644
--- a/content/browser/service_worker/service_worker_version.cc
+++ b/content/browser/service_worker/service_worker_version.cc
@@ -39,6 +39,7 @@
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
+#include "content/public/common/service_registry.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_response_info.h"
 
@@ -754,12 +755,10 @@ void ServiceWorkerVersion::DispatchSyncEvent(const StatusCallback& callback) {
   }
 
   int request_id = AddRequest(callback, &sync_callbacks_, REQUEST_SYNC);
-  ServiceWorkerStatusCode status = embedded_worker_->SendMessage(
-      ServiceWorkerMsg_SyncEvent(request_id));
-  if (status != SERVICE_WORKER_OK) {
-    sync_callbacks_.Remove(request_id);
-    RunSoon(base::Bind(callback, status));
-  }
+  mojo_event_dispatcher_.DispatchSyncEvent(
+      embedded_worker_->process_id(), embedded_worker_->thread_id(),

[michaeln, 2015/06/24 00:12:01]

This won't quite work because ServiceWorkerVersion instances outlive individual
running script instances. A ServiceWorkerVersion can serially start many script
instances in possibly different processes over its lifetime.

food4thought

In the serviceworker codebase, the ServiceWorkerDispatcherHost's is paired with
a particular renderer processes lifetime. Arranging for a mojo_event_dispatcher_
instance to be owned and scoped by ServiceWorkerDispatcherHost might make sense.
The ServiceWorkerContextCore class serves as a registry of sorts. It's a
centrally located class that is reachable by most things and maintains ptrs to
instances of significant other things (see the Add/Remove/GetProviderHost and
Add/Remove/GetLiveXXX methods). Maybe we can Add/Remove/GetSyncEventDispatcher
ptrs as well. Have the dispatcherhost add/rmv the instance it creates for it's
process, and have versions get it by process id as needed.

[iclelland, 2015/06/25 15:17:34]

I've uploaded a new patchset that does just this -- see if it makes sense, and
actually does what you're suggesting here.

+      base::Bind(&self::OnSyncEventFinished, weak_factory_.GetWeakPtr(),
+                 request_id));
 }
 
 void ServiceWorkerVersion::DispatchNotificationClickEvent(
@@ -1174,8 +1173,6 @@ bool ServiceWorkerVersion::OnMessageReceived(const IPC::Message& message) {
                         OnInstallEventFinished)
     IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_FetchEventFinished,
                         OnFetchEventFinished)
-    IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_SyncEventFinished,
-                        OnSyncEventFinished)
     IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_NotificationClickEventFinished,
                         OnNotificationClickEventFinished)
     IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_PushEventFinished,
@@ -1347,9 +1344,8 @@ void ServiceWorkerVersion::OnFetchEventFinished(
   RemoveCallbackAndStopIfRedundant(&fetch_callbacks_, request_id);
 }
 
-void ServiceWorkerVersion::OnSyncEventFinished(
-    int request_id,
-    blink::WebServiceWorkerEventResult result) {
+void ServiceWorkerVersion::OnSyncEventFinished(int request_id,
+                                               ServiceWorkerStatusCode status) {
   TRACE_EVENT1("ServiceWorker",
                "ServiceWorkerVersion::OnSyncEventFinished",
                "Request id", request_id);
@@ -1359,14 +1355,11 @@ void ServiceWorkerVersion::OnSyncEventFinished(
     return;
   }
 
-  ServiceWorkerStatusCode status = SERVICE_WORKER_OK;
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableServiceWorkerSync)) {
     // Avoid potential race condition where flag is disabled after a sync event
     // was dispatched
     status = SERVICE_WORKER_ERROR_ABORT;
-  } else if (result == blink::WebServiceWorkerEventResultRejected) {
-    status = SERVICE_WORKER_ERROR_EVENT_WAITUNTIL_REJECTED;
   }
 
   scoped_refptr<ServiceWorkerVersion> protect(this);