Fix leak in ServiceWorkerVersionTest.RepeatedlyObserveStatusChanges

In r262636 I deleted the Shutdown() methods from SWRegistration and
SWVersion, but it caused a leak in RepeatedlyObserveStatusChanges.

In the previous code the status change callback (ObserveStatusChanges)
holds a ref to ServiceWorkerVersion, which was ok when we had Shutdown()
(as we could explicitly clear the status change callback there), but
now we don't, so we have cyclic reference there.

I just changed make_scoped_refptr(version) to base::Unretained(version)
when we pass the version to the callback, so that the callback no longer
holds a ref to the Version.

BUG=361504
TEST=ServiceWorkerVersionTest.RepeatedlyObserveStatusChanges with asan/lsan

Review URL: https://codereview.chromium.org/230373003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262933 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/service_worker/service_worker_version.cc

@@ -182,7 +182,6 @@ ServiceWorkerVersion::ServiceWorkerVersion(
 }
 
 ServiceWorkerVersion::~ServiceWorkerVersion() {
-  status_change_callbacks_.clear();
   if (embedded_worker_) {
     embedded_worker_->RemoveObserver(this);
     embedded_worker_.reset();

content/browser/service_worker/service_worker_version_unittest.cc

@@ -94,7 +94,7 @@ void ObserveStatusChanges(ServiceWorkerVersion* version,
                           std::vector<ServiceWorkerVersion::Status>* statuses) {
   statuses->push_back(version->status());
   version->RegisterStatusChangeCallback(
-      base::Bind(&ObserveStatusChanges, make_scoped_refptr(version), statuses));
+      base::Bind(&ObserveStatusChanges, base::Unretained(version), statuses));
 }
 
 }  // namespace
@@ -300,7 +300,7 @@ TEST_F(ServiceWorkerVersionTest, ActivateAndWaitCompletion) {
   EXPECT_EQ(ServiceWorkerVersion::ACTIVE, version_->status());
 }
 
-TEST_F(ServiceWorkerVersionTest, DISABLED_RepeatedlyObserveStatusChanges) {
+TEST_F(ServiceWorkerVersionTest, RepeatedlyObserveStatusChanges) {
   EXPECT_EQ(ServiceWorkerVersion::NEW, version_->status());
 
   // Repeatedly observe status changes (the callback re-registers itself).