Use ChildFrameDisconnector when detaching child frames of a LocalFrame.

third_party/WebKit/Source/core/frame/RemoteFrame.h

 // 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.
 
 #ifndef RemoteFrame_h
 #define RemoteFrame_h
 
 #include "core/CoreExport.h"
 #include "core/dom/RemoteSecurityContext.h"
 #include "core/frame/Frame.h"
@@ skipping 53 matching lines @@
 private:
     RemoteFrame(RemoteFrameClient*, FrameHost*, FrameOwner*);
 
     // Internal Frame helper overrides:
     WindowProxyManager* getWindowProxyManager() const override { return m_windowProxyManager.get(); }
     // Intentionally private to prevent redundant checks when the type is
     // already RemoteFrame.
     bool isLocalFrame() const override { return false; }
     bool isRemoteFrame() const override { return true; }
 
+    void detachChildren();
+
     Member<RemoteFrameView> m_view;
     Member<RemoteSecurityContext> m_securityContext;
     Member<RemoteDOMWindow> m_domWindow;
     Member<WindowProxyManager> m_windowProxyManager;
     WebLayer* m_remotePlatformLayer;
 };
 
 inline RemoteFrameView* RemoteFrame::view() const
 {
     return m_view.get();
 }
 
 DEFINE_TYPE_CASTS(RemoteFrame, Frame, remoteFrame, remoteFrame->isRemoteFrame(), remoteFrame.isRemoteFrame());
 
 } // namespace blink
 
 #endif // RemoteFrame_h