Speculative fix for ServiceWorkerOfflineCapabilityCheck flakiness

ServiceWorkerOfflineCapabilityCheckBrowserTest is flaky.
The failure happens when we assert SW's status is ACTIVATED after we await
navigator.serviceWorker.ready. This is, however, is not always true.
Its status can be ACTIVATING.

See https://crbug.com/1041778#c4 for details.

Bug: 1041778
Change-Id: I62ff0ee1a99d05ef693bbf4585a25b6c8831cedd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000400Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Hayato Ito <hayato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#731839}

content/browser/service_worker/service_worker_offline_capability_check_browsertest.cc

@@ -72,7 +72,8 @@ class FetchEventTestHelper {
       scoped_refptr<ServiceWorkerVersion> version) {
     ASSERT_TRUE(
         BrowserThread::CurrentlyOn(ServiceWorkerContext::GetCoreThreadId()));
-    ASSERT_EQ(ServiceWorkerVersion::ACTIVATED, version->status());
+    ASSERT_TRUE(version->status() == ServiceWorkerVersion::ACTIVATING ||
+                version->status() == ServiceWorkerVersion::ACTIVATED);
 
     for (FetchEventDispatch& fetch_event_dispatch : fetch_event_dispatches_) {
       FetchOnCoreThread(done_barrier_closure_on_ui, embedded_test_server,
@@ -644,7 +645,7 @@ IN_PROC_BROWSER_TEST_F(ServiceWorkerOfflineCapabilityCheckBrowserTest,
                                 "/service_worker/create_service_worker.html")));
   EXPECT_EQ("DONE", EvalJs(shell(), "register('maybe_offline_support.js')"));
 
-  // At this point, a service worker's status is ACTIVATED because
+  // At this point, a service worker's status is ACTIVATING or ACTIVATED because
   // register() awaits navigator.serviceWorker.ready promise.
 
   EXPECT_EQ(OfflineCapability::kUnsupported,