Background Sync: Use 1-based ref-counting with BackgroundSyncContext.

TBR: jam
Change-Id: I205f31a13db8b5bb990627c190a9c4d8c2cb156f
Reviewed-on: https://chromium-review.googlesource.com/1055204
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Josh Karlin <jkarlin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557929}

content/browser/background_sync/background_sync_context.h

@@ -25,6 +25,8 @@ class ServiceWorkerContextWrapper;
 class CONTENT_EXPORT BackgroundSyncContext
     : public base::RefCountedDeleteOnSequence<BackgroundSyncContext> {
  public:
+  REQUIRE_ADOPTION_FOR_REFCOUNTED_TYPE();
+
   BackgroundSyncContext();
 
   // Init and Shutdown are for use on the UI thread when the

content/browser/background_sync/background_sync_service_impl_unittest.cc

@@ -142,7 +142,8 @@ class BackgroundSyncServiceImplTest : public testing::Test {
   void CreateBackgroundSyncContext() {
     // Registering for background sync includes a check for having a same-origin
     // main frame. Use a test context that allows control over that check.
-    background_sync_context_ = new TestBackgroundSyncContext();
+    background_sync_context_ =
+        base::MakeRefCounted<TestBackgroundSyncContext>();
     background_sync_context_->Init(embedded_worker_helper_->context_wrapper());
 
     // Tests do not expect the sync event to fire immediately after

content/browser/storage_partition_impl.cc

@@ -628,7 +628,8 @@ std::unique_ptr<StoragePartitionImpl> StoragePartitionImpl::Create(
   partition->background_fetch_context_ =
       new BackgroundFetchContext(context, partition->service_worker_context_);
 
-  partition->background_sync_context_ = new BackgroundSyncContext();
+  partition->background_sync_context_ =
+      base::MakeRefCounted<BackgroundSyncContext>();
   partition->background_sync_context_->Init(partition->service_worker_context_);
 
   partition->payment_app_context_ = new PaymentAppContextImpl();