The Service Worker notificationclick event should carry a notification.

Source/modules/notifications/Notification.h

Index: Source/modules/notifications/Notification.h
diff --git a/Source/modules/notifications/Notification.h b/Source/modules/notifications/Notification.h
index 54b0ae4f9e75c543bfc57d819f2884f7f60208fa..3942dcc356fe87711780d3ef2813519663f3da24 100644
--- a/Source/modules/notifications/Notification.h
+++ b/Source/modules/notifications/Notification.h
@@ -47,14 +47,20 @@ namespace blink {
 class ExecutionContext;
 class NotificationOptions;
 class NotificationPermissionCallback;
+struct WebNotificationData;
 
 class Notification : public RefCountedGarbageCollectedWillBeGarbageCollectedFinalized<Notification>, public ActiveDOMObject, public EventTargetWithInlineData, public WebNotificationDelegate {
     DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<Notification>);
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Notification);
 public:
+    // Used for JavaScript instantiations of the Notification object. Will automatically schedule for
+    // the notification to be displayed to the user.
     static Notification* create(ExecutionContext*, const String& title, const NotificationOptions&);
 
+    // Used for embedder-created Notification objects. Will initialize the Notification's state as showing.
+    static Notification* create(ExecutionContext*, const String& persistentId, const WebNotificationData&);
+
     virtual ~Notification();
 
     void close();
@@ -97,6 +103,8 @@ public:
 private:
     Notification(const String& title, ExecutionContext*);
 
+    void scheduleShow();
+
     // Calling show() may start asynchronous operation. If this object has
     // a V8 wrapper, hasPendingActivity() prevents the wrapper from being
     // collected while m_state is Showing, and so this instance stays alive
@@ -110,6 +118,8 @@ private:
     void setIconUrl(KURL iconUrl) { m_iconUrl = iconUrl; }
     void setTag(const String& tag) { m_tag = tag; }
 
+    void setPersistentId(const String& persistentId) { m_persistentId = persistentId; }
+
 private:
     String m_title;
     String m_dir;
@@ -119,12 +129,21 @@ private:
 
     KURL m_iconUrl;
 
+    // Notifications can either be bound to the page, which means they're identified by
+    // their delegate, or persistent, which means they're identified by a persistent Id
+    // given to us by the embedder. This influences how we close the notification.
+    String m_persistentId;
+
     enum NotificationState {
         NotificationStateIdle,
         NotificationStateShowing,
         NotificationStateClosed
     };
 
+    // Only to be used by the Notification::create() method when notifications were created
+    // by the embedder rather than by Blink.
+    void setState(NotificationState state) { m_state = state; }
+
     NotificationState m_state;
 
     AsyncMethodRunner<Notification> m_asyncRunner;