Populate the response blob for finished Background Fetches

content/browser/background_fetch/background_fetch_context.cc

 // Copyright 2017 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/background_fetch/background_fetch_context.h"
 
 #include "base/memory/ptr_util.h"
 #include "content/browser/background_fetch/background_fetch_data_manager.h"
 #include "content/browser/background_fetch/background_fetch_event_dispatcher.h"
 #include "content/browser/background_fetch/background_fetch_job_controller.h"
@@ skipping 156 matching lines @@
       controller->registration_id();
 
   DCHECK_GT(active_fetches_.count(registration_id), 0u);
 
   // TODO(peter): Fire `backgroundfetchabort` if the |controller|'s state is
   // ABORTED, which does not require a sequence of the settled fetches.
 
   // The `backgroundfetched` and/or `backgroundfetchfail` event will only be
   // invoked for Background Fetch jobs which have been completed.
   if (controller->state() != BackgroundFetchJobController::State::COMPLETED) {
-    DeleteRegistration(registration_id);
+    DeleteRegistration(registration_id,
+                       std::vector<std::unique_ptr<BlobHandle>>());
     return;
   }
 
   // Get the sequence of settled fetches from the data manager.
   data_manager_->GetSettledFetchesForRegistration(
       registration_id,
       base::BindOnce(&BackgroundFetchContext::DidGetSettledFetches, this,
                      registration_id));
 }
 
 void BackgroundFetchContext::DidGetSettledFetches(
     const BackgroundFetchRegistrationId& registration_id,
     blink::mojom::BackgroundFetchError error,
     std::vector<BackgroundFetchSettledFetch> settled_fetches,
     std::vector<std::unique_ptr<BlobHandle>> blob_handles) {
   if (error != blink::mojom::BackgroundFetchError::NONE) {
-    DeleteRegistration(registration_id);
+    DeleteRegistration(registration_id, std::move(blob_handles));
     return;
   }
 
   // TODO(peter): Distinguish between the `backgroundfetched` and
   // `backgroundfetchfail` events based on the status code of all fetches. We
   // don't populate that field yet, so always assume it's successful for now.
 
   event_dispatcher_->DispatchBackgroundFetchedEvent(
       registration_id, std::move(settled_fetches),
       base::Bind(&BackgroundFetchContext::DeleteRegistration, this,
-                 registration_id));
+                 registration_id, std::move(blob_handles)));
 }
 
 void BackgroundFetchContext::DeleteRegistration(
-    const BackgroundFetchRegistrationId& registration_id) {
+    const BackgroundFetchRegistrationId& registration_id,
+    const std::vector<std::unique_ptr<BlobHandle>>& blob_handles) {

[harkness, 2017/04/05 09:26:00]

Why do you think we're going to need the blob handles in the delete? At this
point I don't see the ownership on the handles being held anywhere in the
background fetch system.

[Peter Beverloo, 2017/04/05 09:39:27]

We don't, but we need to keep the handles alive for the duration of the event.
(This is the callback passed to
EventDispatcher::DispatchBackgroundFetchedEvent.)

   DCHECK_GT(active_fetches_.count(registration_id), 0u);
 
   // Delete all persistent information associated with the |registration_id|.
   data_manager_->DeleteRegistration(
       registration_id, base::BindOnce(&RecordRegistrationDeletedError));
 
   // Delete the local state associated with the |registration_id|.
   active_fetches_.erase(registration_id);
 }
 
 }  // namespace content