compositor-worker: Force elements to grow a layer when a CompositorProxy is created.

Source/core/style/StyleRareNonInheritedData.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 191 matching lines @@
 
     // Plugins require accelerated compositing for reasons external to blink.
     // In which case, we need to update the ComputedStyle on the LayoutEmbeddedObject,
     // so store this bit so that the style actually changes when the plugin
     // becomes composited.
     unsigned m_requiresAcceleratedCompositingForExternalReasons: 1;
 
     // Whether the transform (if it exists) is stored in the element's inline style.
     unsigned m_hasInlineTransform : 1;
     unsigned m_resize : 2; // EResize
+    unsigned m_hasCompositorProxy : 1;
 
 private:
     StyleRareNonInheritedData();
     StyleRareNonInheritedData(const StyleRareNonInheritedData&);
 };
 
 } // namespace blink
 
 #endif // StyleRareNonInheritedData_h