Oilpan: add missing tracing of PopupMenuImpl::m_chromeClient.

third_party/WebKit/Source/web/PopupMenuImpl.cpp

 // Copyright (c) 2014 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 "web/PopupMenuImpl.h"
 
 #include "core/HTMLNames.h"
 #include "core/css/CSSFontSelector.h"
 #include "core/dom/ElementTraversal.h"
@@ skipping 236 matching lines @@
 {
 }
 
 PopupMenuImpl::~PopupMenuImpl()
 {
     ASSERT(!m_popup);
 }
 
 DEFINE_TRACE(PopupMenuImpl)
 {
+    visitor->trace(m_chromeClient);
     visitor->trace(m_ownerElement);
     PopupMenu::trace(visitor);
 }
 
 IntSize PopupMenuImpl::contentSize()
 {
     return IntSize();
 }
 
 void PopupMenuImpl::writeDocument(SharedBuffer* data)
@@ skipping 254 matching lines @@
 
 void PopupMenuImpl::disconnectClient()
 {
     m_ownerElement = nullptr;
     // Cannot be done during finalization, so instead done when the
     // layout object is destroyed and disconnected.
     dispose();
 }
 
 } // namespace blink