Enable Oilpan for core/timing/.

Source/core/timing/DOMWindowPerformance.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/timing/DOMWindowPerformance.h"
 
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/timing/Performance.h"
 
 namespace blink {
 
 DOMWindowPerformance::DOMWindowPerformance(LocalDOMWindow& window)
     : DOMWindowProperty(window.frame())
-    , m_window(window)
+    , m_window(&window)
 {
 }
 
 DEFINE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(DOMWindowPerformance);
 
 DEFINE_TRACE(DOMWindowPerformance)
 {
+    visitor->trace(m_window);
     visitor->trace(m_performance);
     WillBeHeapSupplement<LocalDOMWindow>::trace(visitor);
     DOMWindowProperty::trace(visitor);
 }
 
 // static
 const char* DOMWindowPerformance::supplementName()
 {
     return "DOMWindowPerformance";
 }
@@ skipping 11 matching lines @@
 
 // static
 Performance* DOMWindowPerformance::performance(DOMWindow& window)
 {
     return from(toLocalDOMWindow(window)).performance();
 }
 
 Performance* DOMWindowPerformance::performance()
 {
     if (!m_performance)
-        m_performance = Performance::create(m_window.frame());
+        m_performance = Performance::create(m_window->frame());
     return m_performance.get();
 }
 
 } // namespace blink