[merge to M53] Make sure Widget::dispose() respects UpdateSuspendScope.

third_party/WebKit/Source/core/html/HTMLFrameOwnerElement.h

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 75 matching lines @@
     const WebVector<WebPermissionType>& delegatedPermissions() const override;
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     HTMLFrameOwnerElement(const QualifiedName& tagName, Document&);
     void setSandboxFlags(SandboxFlags);
 
     bool loadOrRedirectSubframe(const KURL&, const AtomicString& frameName, bool replaceCurrentItem);
 
+    void disposeWidgetSoon(Widget*);
+
 private:
     // Intentionally private to prevent redundant checks when the type is
     // already HTMLFrameOwnerElement.
     bool isLocal() const override { return true; }
     bool isRemote() const override { return false; }
 
     bool isKeyboardFocusable() const override;
     bool isFrameOwnerElement() const final { return true; }
 
     virtual ReferrerPolicy referrerPolicyAttribute() { return ReferrerPolicyDefault; }
@@ skipping 40 matching lines @@
     CORE_EXPORT static SubtreeRootSet& disabledSubtreeRoots();
 
     Member<Node> m_root;
 };
 
 DEFINE_TYPE_CASTS(HTMLFrameOwnerElement, FrameOwner, owner, owner->isLocal(), owner.isLocal());
 
 } // namespace blink
 
 #endif // HTMLFrameOwnerElement_h