Move Frame pointer to be held by DOMWindow base class.

third_party/WebKit/Source/core/frame/DOMWindow.cpp

 // Copyright 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 "core/frame/DOMWindow.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/dom/SecurityContext.h"
@@ skipping 16 matching lines @@
 #include "core/page/ChromeClient.h"
 #include "core/page/FocusController.h"
 #include "core/page/Page.h"
 #include "platform/weborigin/KURL.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "platform/weborigin/Suborigin.h"
 #include <memory>
 
 namespace blink {
 
-DOMWindow::DOMWindow() : m_windowIsClosing(false) {}
+DOMWindow::DOMWindow(Frame& frame) : m_frame(frame), m_windowIsClosing(false) {}
 
-DOMWindow::~DOMWindow() {}
+DOMWindow::~DOMWindow() {
+  // The frame must be disconnected before finalization.
+  DCHECK(!m_frame);
+}
 
 v8::Local<v8::Object> DOMWindow::wrap(v8::Isolate*,
                                       v8::Local<v8::Object> creationContext) {
   LOG(FATAL) << "DOMWindow must never be wrapped with wrap method.  The "
                 "wrappers must be created at WindowProxy::createContext() and "
                 "setupWindowPrototypeChain().";
   return v8::Local<v8::Object>();
 }
 
 v8::Local<v8::Object> DOMWindow::associateWithWrapper(
@@ skipping 375 matching lines @@
   }
 
   // If we're a top level window, bring the window to the front.
   if (frame()->isMainFrame() && allowFocus)
     page->chromeClient().focus();
 
   page->focusController().focusDocumentView(frame(), true /* notifyEmbedder */);
 }
 
 DEFINE_TRACE(DOMWindow) {
+  visitor->trace(m_frame);
   visitor->trace(m_location);
   EventTargetWithInlineData::trace(visitor);
 }
 
 }  // namespace blink