Add missing traces for Supplement<> classes

third_party/WebKit/Source/modules/webdatabase/DatabaseClient.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 26 matching lines @@
 
 namespace blink {
 
 DatabaseClient::DatabaseClient()
     : m_inspectorAgent(nullptr)
 { }
 
 DEFINE_TRACE(DatabaseClient)
 {
     visitor->trace(m_inspectorAgent);
+    Supplement<Page>::trace(visitor);
 }
 
 DatabaseClient* DatabaseClient::fromPage(Page* page)
 {
     return static_cast<DatabaseClient*>(Supplement<Page>::from(page, supplementName()));
 }
 
 DatabaseClient* DatabaseClient::from(ExecutionContext* context)
 {
     return DatabaseClient::fromPage(toDocument(context)->page());
@@ skipping 15 matching lines @@
     // TODO(dgozman): we should not set agent twice, but it's happening in OOPIF case.
     m_inspectorAgent = agent;
 }
 
 void provideDatabaseClientTo(Page& page, DatabaseClient* client)
 {
     page.provideSupplement(DatabaseClient::supplementName(), client);
 }
 
 } // namespace blink