Decouple FileSystem and WebSQL callbacks from VoidCallback and it non-refcounted

Source/modules/notifications/NotificationClient.h

Index: Source/modules/notifications/NotificationClient.h
diff --git a/Source/modules/notifications/NotificationClient.h b/Source/modules/notifications/NotificationClient.h
index 56e962b7f92267e32188127596795fa767b6e780..4a0e44f528f70a4b77f9c1a7cdf51a861fcf32be 100644
--- a/Source/modules/notifications/NotificationClient.h
+++ b/Source/modules/notifications/NotificationClient.h
@@ -75,7 +75,7 @@ public:
     // Requests user permission to show desktop notifications from a particular
     // script context. The callback parameter should be run when the user has
     // made a decision.
-    virtual void requestPermission(ExecutionContext*, PassRefPtr<VoidCallback>) = 0;
+    virtual void requestPermission(ExecutionContext*, PassOwnPtr<VoidCallback>) = 0;
 #endif
     virtual void requestPermission(ExecutionContext*, PassOwnPtr<NotificationPermissionCallback>) = 0;