NotificationController::clientFrom() should return a reference

NotificationController has maintained NotificationClient with OwnPtr since r173468. And, NotificationClient should not be a null. We can return a reference on NotificationController::clientFrom().

BUG=none

Review URL: https://codereview.chromium.org/268353004

git-svn-id: svn://svn.chromium.org/blink/trunk@175795 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/modules/notifications/Notification.cpp

@@ -43,8 +43,8 @@ namespace WebCore {
 
 Notification* Notification::create(ExecutionContext* context, const String& title, const Dictionary& options)
 {
-    NotificationClient* client = NotificationController::clientFrom(toDocument(context)->frame());
-    Notification* notification = adoptRefCountedGarbageCollected(new Notification(title, context, client));
+    NotificationClient& client = NotificationController::clientFrom(toDocument(context)->frame());
+    Notification* notification = adoptRefCountedGarbageCollected(new Notification(title, context, &client));
 
     String argument;
     if (options.get("body", argument))
@@ -89,7 +89,7 @@ void Notification::show()
     if (!toDocument(executionContext())->page())
         return;
 
-    if (NotificationController::from(toDocument(executionContext())->frame())->client()->checkPermission(executionContext()) != NotificationClient::PermissionAllowed) {
+    if (m_client->checkPermission(executionContext()) != NotificationClient::PermissionAllowed) {
         dispatchErrorEvent();
         return;
     }
@@ -164,13 +164,13 @@ const String& Notification::permission(ExecutionContext* context)
     ASSERT(toDocument(context)->page());
 
     UseCounter::count(context, UseCounter::NotificationPermission);
-    return permissionString(NotificationController::from(toDocument(context)->frame())->client()->checkPermission(context));
+    return permissionString(NotificationController::clientFrom(toDocument(context)->frame()).checkPermission(context));
 }
 
 void Notification::requestPermission(ExecutionContext* context, PassOwnPtr<NotificationPermissionCallback> callback)
 {
     ASSERT(toDocument(context)->page());
-    NotificationController::from(toDocument(context)->frame())->client()->requestPermission(context, callback);
+    NotificationController::clientFrom(toDocument(context)->frame()).requestPermission(context, callback);
 }
 
 bool Notification::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)

third_party/WebKit/Source/modules/notifications/NotificationController.cpp

@@ -45,11 +45,11 @@ PassOwnPtr<NotificationController> NotificationController::create(PassOwnPtr<Not
     return adoptPtr(new NotificationController(client));
 }
 
-NotificationClient* NotificationController::clientFrom(LocalFrame* frame)
+NotificationClient& NotificationController::clientFrom(LocalFrame* frame)
 {
-    if (NotificationController* controller = NotificationController::from(frame))
-        return controller->client();
-    return 0;
+    NotificationController* controller = NotificationController::from(frame);
+    ASSERT(controller);
+    return controller->client();
 }
 
 const char* NotificationController::supplementName()

third_party/WebKit/Source/modules/notifications/NotificationController.h

@@ -42,15 +42,15 @@ public:
     static PassOwnPtr<NotificationController> create(PassOwnPtr<NotificationClient>);
     static const char* supplementName();
     static NotificationController* from(LocalFrame* frame) { return static_cast<NotificationController*>(Supplement<LocalFrame>::from(frame, supplementName())); }
-    static NotificationClient* clientFrom(LocalFrame*);
-
-    NotificationClient* client() { return m_client.get(); }
+    static NotificationClient& clientFrom(LocalFrame*);
 
     virtual void trace(Visitor* visitor) OVERRIDE { Supplement<LocalFrame>::trace(visitor); }
 
 private:
     explicit NotificationController(PassOwnPtr<NotificationClient>);
 
+    NotificationClient& client() { return *m_client; }
+
     OwnPtr<NotificationClient> m_client;
 };