Add ref count to service workers for extension API.

chrome/browser/extensions/service_worker_apitest.cc

Index: chrome/browser/extensions/service_worker_apitest.cc
diff --git a/chrome/browser/extensions/service_worker_apitest.cc b/chrome/browser/extensions/service_worker_apitest.cc
index 227584f99c1a1880ce3d64f2582357edeecf58e3..3259da7f8e5b4972b91584e2007adcb329fbf38a 100644
--- a/chrome/browser/extensions/service_worker_apitest.cc
+++ b/chrome/browser/extensions/service_worker_apitest.cc
@@ -622,7 +622,11 @@ IN_PROC_BROWSER_TEST_F(ServiceWorkerTest, TabsCreate) {
   std::string result;
   ASSERT_TRUE(content::ExecuteScriptAndExtractString(
       web_contents, "window.runServiceWorker()", &result));
-  ASSERT_EQ("chrome.tabs.create callback", result);
+  // TODO(lazyboy): Test that after we issue the extension API call, the worker
+  // doesn't terminate until the API returns, even if the API returns after the
+  // worker's timeout expires. The extension API is supposed to add ref count
+  // to the worker and keep it running.
+  ASSERT_EQ("chrome.tabs.update callback", result);
   EXPECT_EQ(starting_tab_count + 1, browser()->tab_strip_model()->count());
 
   // Check extension shutdown path.