Move plugins to be stored in HTMLPlugInElement.

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

 /*
  * Copyright (C) 2006, 2008, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 24 matching lines @@
 
 class CORE_EXPORT PluginDocument final : public HTMLDocument {
  public:
   static PluginDocument* create(
       const DocumentInit& initializer = DocumentInit()) {
     return new PluginDocument(initializer);
   }
 
   void setPluginNode(Node* pluginNode) { m_pluginNode = pluginNode; }
 
+  // TODO(joelhockey): This method does not need to be public, and hardly needs
+  // to exist at all.
   PluginView* pluginView();
   Node* pluginNode();
 
   void shutdown() override;
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   explicit PluginDocument(const DocumentInit&);
 
   DocumentParser* createParser() override;
 
   Member<Node> m_pluginNode;
 };
 
 DEFINE_DOCUMENT_TYPE_CASTS(PluginDocument);
 
 }  // namespace blink
 
 #endif  // PluginDocument_h