Remove ContextClient from DOMWindowPerformance

third_party/WebKit/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 "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)
-    : ContextClient(window.frame()), m_window(&window) {}
+    : Supplement<LocalDOMWindow>(window) {}
 
 DEFINE_TRACE(DOMWindowPerformance) {
-  visitor->trace(m_window);
   visitor->trace(m_performance);
   Supplement<LocalDOMWindow>::trace(visitor);
-  ContextClient::trace(visitor);
 }
 
 // static
 const char* DOMWindowPerformance::supplementName() {
   return "DOMWindowPerformance";
 }
 
 // static
 DOMWindowPerformance& DOMWindowPerformance::from(LocalDOMWindow& window) {
   DOMWindowPerformance* supplement = static_cast<DOMWindowPerformance*>(
       Supplement<LocalDOMWindow>::from(window, supplementName()));
   if (!supplement) {
     supplement = new DOMWindowPerformance(window);
     provideTo(window, supplementName(), supplement);
   }
   return *supplement;
 }
 
 // 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(host()->frame());
   return m_performance.get();
 }
 
 }  // namespace blink