Move push event dispatching out of ServiceWorkerVersion.

content/browser/push_messaging/push_messaging_router.cc

Index: content/browser/push_messaging/push_messaging_router.cc
diff --git a/content/browser/push_messaging/push_messaging_router.cc b/content/browser/push_messaging/push_messaging_router.cc
index bc95216ad07698514323caf241f6a1542273660d..e2b295e1e4e42f566c080bb03df2567d526ebe67 100644
--- a/content/browser/push_messaging/push_messaging_router.cc
+++ b/content/browser/push_messaging/push_messaging_router.cc
@@ -10,6 +10,7 @@
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
 #include "content/browser/service_worker/service_worker_registration.h"
 #include "content/browser/service_worker/service_worker_storage.h"
+#include "content/common/service_worker/service_worker_messages.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
@@ -22,6 +23,7 @@ namespace {
 void RunDeliverCallback(
     const PushMessagingRouter::DeliverMessageCallback& deliver_message_callback,
     PushDeliveryStatus delivery_status) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(deliver_message_callback, delivery_status));
@@ -90,8 +92,14 @@ void PushMessagingRouter::FindServiceWorkerRegistrationCallback(
   base::Callback<void(ServiceWorkerStatusCode)> dispatch_event_callback =
       base::Bind(&PushMessagingRouter::DeliverMessageEnd,
                  deliver_message_callback, service_worker_registration);
-
-  version->DispatchPushEvent(dispatch_event_callback, data);
+  version->RunAfterStartWorker(

[johnme, 2016/01/22 14:35:37]

Nit: If you made DispatchSimpleEvent automatically handle the
RunAfterStartWorker part, this could be even simpler:

ServiceWorkerVersion
    ::DispatchSimpleEvent<ServiceWorkerMsg_PushEvent,
                          ServiceWorkerHostMsg_PushEventFinished,
                          std::string>(
    version, ServiceWorkerMetrics::EventType::PUSH,
    dispatch_event_callback, data);

[Marijn Kruisselbrink, 2016/01/23 00:02:19]

A prerequisite for that merge would be to merge RunAfterStartWorker with
StartRequest. And if/when those two are merged (as in StartRequest can function
without an already running worker) there really is no benefit anymore in merging
StartRequest with DispatchEvent since then you could just synchronously call one
after the other while SWVersion does all the correct queueing.
That is something I'd love to do, but I'd prefer to wait until after I finished
migrating all the events to use StartRequest so I can first simplify the request
tracking in SWVersion to not have to care about multiple request types anymore.

+      base::Bind(base::IgnoreResult(
+                     &ServiceWorkerVersion::DispatchSimpleEvent<
+                         ServiceWorkerMsg_PushEvent,
+                         ServiceWorkerHostMsg_PushEventFinished, std::string>),
+                 version, ServiceWorkerMetrics::EventType::PUSH,
+                 dispatch_event_callback, data),
+      dispatch_event_callback);
 }
 
 // static