Add layout tests for ServiceWorker's notificationclose event.

content/shell/browser/layout_test/layout_test_notification_manager.cc

Index: content/shell/browser/layout_test/layout_test_notification_manager.cc
diff --git a/content/shell/browser/layout_test/layout_test_notification_manager.cc b/content/shell/browser/layout_test/layout_test_notification_manager.cc
index f4f1864b15456d64180cb520fdec725a35079c51..77584f05124bae8d573b148a49f1e7e5724ce46a 100644
--- a/content/shell/browser/layout_test/layout_test_notification_manager.cc
+++ b/content/shell/browser/layout_test/layout_test_notification_manager.cc
@@ -134,6 +134,32 @@ void LayoutTestNotificationManager::SimulateClick(const std::string& title,
           base::Bind(&OnEventDispatchComplete));
 }
 
+void LayoutTestNotificationManager::SimulateClose(const std::string& title,
+                                                  bool by_user) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // First check for page-notifications with the given title.
+  const auto& page_iterator = page_notifications_.find(title);
+  if (page_iterator != page_notifications_.end()) {
+    page_iterator->second->NotificationClosed();

[Peter Beverloo, 2016/02/02 23:50:10]

No need to check for in-page notifications here - those code paths are already
exercised by programmatically closing the notification.

[Nina, 2016/02/03 15:04:23]

Removed.

+    return;
+  }
+
+  // Then check for persistent notifications with the given title.
+  const auto& persistent_iterator = persistent_notifications_.find(title);
+  if (persistent_iterator == persistent_notifications_.end())
+    return;
+
+  const PersistentNotification& notification = persistent_iterator->second;
+  content::NotificationEventDispatcher::GetInstance()
+      ->DispatchNotificationCloseEvent(
+          notification.browser_context,
+          notification.persistent_id,
+          notification.origin,
+          by_user,
+          base::Bind(&OnEventDispatchComplete));
+}
+
 blink::WebNotificationPermission
 LayoutTestNotificationManager::CheckPermissionOnUIThread(
     BrowserContext* browser_context,