[Proof-of-concept] PlzNavigate and Service Worker

content/browser/service_worker/service_worker_dispatcher_host.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/service_worker_dispatcher_host.h"
 
 #include "base/logging.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 679 matching lines @@
   }
 
   handle->version()->DispatchMessageEvent(
       message, sent_message_ports,
       base::Bind(&ServiceWorkerUtils::NoOpStatusCallback));
 }
 
 void ServiceWorkerDispatcherHost::OnProviderCreated(
     int provider_id,
     int route_id,
-    ServiceWorkerProviderType provider_type) {
+    ServiceWorkerProviderType provider_type,
+    int navigation_provider_id) {

[michaeln, 2015/07/30 01:35:08]

i don't like long names but 'nav_provider_id' is very generic and i can imagine
that random sw engineer will have a hard time figuring out what the int value
refers too when seeing it here and there (and there and there). i wish
'plznavigate' were actually used in symbol names because that term is very
informative, i see its used in comments everywhere, if it were used for
class/variable naming lots of the comments wouldn't be needed.

anyway, long winded way of saying... consider renaming this param to something
more informative like 'plznavigate_service_worker_provider_id' through out

alternatively, see other comments about using 'request_id_' as the basis of
identifying plaz navigate reques, and adopting the swproviderhost at InitHandler
time.

[Fabrice (no longer in Chrome), 2015/08/06 15:39:15]

Not using PlzNavigate prefix in variable/class names is a design choice as
PlzNavigate will entirely replace current navigations so please do not use that.
I agree this can be confusing in the meantime while we are transitioning and
have to support both code paths.
I'm not clear on what navigation_

   // TODO(pkasting): Remove ScopedTracker below once crbug.com/477117 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "477117 ServiceWorkerDispatcherHost::OnProviderCreated"));
   TRACE_EVENT0("ServiceWorker",
                "ServiceWorkerDispatcherHost::OnProviderCreated");
   if (!GetContext())
     return;
   if (GetContext()->GetProviderHost(render_process_id_, provider_id)) {
     bad_message::ReceivedBadMessage(this,
                                     bad_message::SWDH_PROVIDER_CREATED_NO_HOST);
     return;
   }
+
+  // PlzNavigate:
+  if (navigation_provider_id != kInvalidServiceWorkerProviderId) {
+    DCHECK_EQ(SERVICE_WORKER_PROVIDER_FOR_WINDOW, provider_type);
+    scoped_ptr<ServiceWorkerProviderHost> navigation_provider_host(
+        GetContext()->TakeNavigationProviderHost(navigation_provider_id));
+    DCHECK(navigation_provider_host);

[michaeln, 2015/07/30 01:35:08]

we can't trust these values are legit, !nav_provider_host here probably warrants
a bad_message::ReceivedBadMessage call

+    navigation_provider_host->CompleteCrossSiteTransfer(
+        render_process_id_, route_id, provider_id, provider_type, this);
+    GetContext()->AddProviderHost(navigation_provider_host.Pass());
+    return;
+  }
+
   scoped_ptr<ServiceWorkerProviderHost> provider_host(
       new ServiceWorkerProviderHost(render_process_id_, route_id, provider_id,
                                     provider_type, GetContext()->AsWeakPtr(),
                                     this));
   GetContext()->AddProviderHost(provider_host.Pass());
 }
 
 void ServiceWorkerDispatcherHost::OnProviderDestroyed(int provider_id) {
   TRACE_EVENT0("ServiceWorker",
                "ServiceWorkerDispatcherHost::OnProviderDestroyed");
@@ skipping 492 matching lines @@
   if (!handle) {
     bad_message::ReceivedBadMessage(this,
                                     bad_message::SWDH_TERMINATE_BAD_HANDLE);
     return;
   }
   handle->version()->StopWorker(
       base::Bind(&ServiceWorkerUtils::NoOpStatusCallback));
 }
 
 }  // namespace content