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..a18718b653ecf6dc893d785c43deaeae0e32a28e 100644
--- a/chrome/browser/extensions/service_worker_apitest.cc
+++ b/chrome/browser/extensions/service_worker_apitest.cc
@@ -24,6 +24,8 @@
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/permission_type.h"
+#include "content/public/browser/service_worker_context.h"
+#include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/origin_util.h"
@@ -93,6 +95,12 @@ class ServiceWorkerTest : public ExtensionApiTest {
 
   ~ServiceWorkerTest() override {}
 
+  void DidGetPendingExternalRequestCount(const base::Closure& callback,
+                                         size_t external_request_count) {
+    last_worker_ref_count_ = external_request_count;
+    callback.Run();
+  }
+
  protected:
   // Returns the ProcessManager for the test's profile.
   ProcessManager* process_manager() { return ProcessManager::Get(profile()); }
@@ -162,6 +170,8 @@ class ServiceWorkerTest : public ExtensionApiTest {
     return ExtractInnerText(Navigate(url));
   }
 
+  size_t last_worker_ref_count() const { return last_worker_ref_count_; }
+
  private:
   // Sets the channel to "stable".
   // Not useful after we've opened extension Service Workers to stable
@@ -170,6 +180,8 @@ class ServiceWorkerTest : public ExtensionApiTest {
   // removed.
   ScopedCurrentChannel current_channel_;
 
+  size_t last_worker_ref_count_ = 0u;
+
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerTest);
 };
 
@@ -630,6 +642,52 @@ IN_PROC_BROWSER_TEST_F(ServiceWorkerTest, TabsCreate) {
   EXPECT_EQ(starting_tab_count, browser()->tab_strip_model()->count());
 }
 
+// Tests that worker ref count increments while extension API function is
+// active.
+IN_PROC_BROWSER_TEST_F(ServiceWorkerTest, WorkerRefCount) {
+  // Extensions APIs from SW are only enabled on trunk.
+  ScopedCurrentChannel current_channel_override(version_info::Channel::UNKNOWN);
+  const Extension* extension = LoadExtensionWithFlags(
+      test_data_dir_.AppendASCII("service_worker/api_worker_ref_count"),
+      kFlagNone);
+  ASSERT_TRUE(extension);
+  ui_test_utils::NavigateToURL(browser(),
+                               extension->GetResourceURL("page.html"));
+  content::WebContents* web_contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+

[Devlin, 2016/10/07 15:13:22]

Check ref count is 0?

[lazyboy, 2016/10/07 18:50:10]

Done.

+  ExtensionTestMessageListener worker_listener("CHECK_REF_COUNT", true);
+  worker_listener.set_failure_message("FAILURE");
+  ASSERT_TRUE(
+      content::ExecuteScript(web_contents, "window.runServiceWorker()"));
+  ASSERT_TRUE(worker_listener.WaitUntilSatisfied());
+
+  {
+    content::ServiceWorkerContext* sw_context =
+        content::BrowserContext::GetDefaultStoragePartition(
+            browser()->profile())
+            ->GetServiceWorkerContext();
+    base::RunLoop run_loop;
+    sw_context->GetPendingExternalRequestCountForTest(
+        extension->url(),
+        base::Bind(&ServiceWorkerTest::DidGetPendingExternalRequestCount,
+                   // Unretained is safe because we wait until the bound method
+                   // is called.
+                   base::Unretained(this), run_loop.QuitClosure()));
+    run_loop.Run();
+  }
+
+  // Service worker should have exactly one pending request because
+  // chrome.test.sendMessage() API call is in-flight.
+  EXPECT_EQ(1u, last_worker_ref_count());
+
+  ExtensionTestMessageListener extension_listener("SUCCESS", false);
+  extension_listener.set_failure_message("FAILURE");
+  // Finish executing chrome.test.sendMessage().
+  worker_listener.Reply("Hello world");
+  ASSERT_TRUE(extension_listener.WaitUntilSatisfied());

[Devlin, 2016/10/07 15:13:21]

Check that ref count drops to 0?

I also wonder if it's worth checking that adding two methods increases it to 2 -
just to cover all the bases of 0, 1, >1.

[lazyboy, 2016/10/07 18:50:10]

Done.
Done.

+}
+
 // This test loads a web page that has an iframe pointing to a
 // chrome-extension:// URL. The URL is listed in the extension's
 // web_accessible_resources. Initially the iframe is served from the extension's