Remove the lifetime hack in ImageLoader where it keeps its assoc element alive

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2012 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef HTMLPlugInElement_h
 #define HTMLPlugInElement_h
 
 #include "core/CoreExport.h"
 #include "core/html/HTMLFrameOwnerElement.h"
+#include "platform/bindings/ActiveScriptWrappable.h"
 #include "platform/bindings/SharedPersistent.h"
 #include "v8/include/v8.h"
 
 namespace blink {
 
 class HTMLImageLoader;
 class LayoutPart;
 class LayoutEmbeddedItem;
 class PluginView;
 
 enum PreferPlugInsForImagesOption {
   kShouldPreferPlugInsForImages,
   kShouldNotPreferPlugInsForImages
 };
 
-class CORE_EXPORT HTMLPlugInElement : public HTMLFrameOwnerElement {
+class CORE_EXPORT HTMLPlugInElement
+    : public HTMLFrameOwnerElement,
+      public ActiveScriptWrappable<HTMLPlugInElement> {
+  USING_GARBAGE_COLLECTED_MIXIN(HTMLPlugInElement);
+
  public:
   ~HTMLPlugInElement() override;
   DECLARE_VIRTUAL_TRACE();
 
+  bool HasPendingActivity() const final;
+
   void SetFocused(bool, WebFocusType) override;
   void ResetInstance();
   // TODO(dcheng): Consider removing this, since HTMLEmbedElementLegacyCall
   // and HTMLObjectElementLegacyCall usage is extremely low.
   v8::Local<v8::Object> PluginWrapper();
   // TODO(joelhockey): Clean up PluginWidget and OwnedPlugin (maybe also
   // PluginWrapper).  It would be good to remove and/or rename some of these.
   // PluginWidget and OwnedPlugin both return the plugin that is stored as
   // widget in HTMLFrameOwnerElement.  However PluginWidget will synchronously
   // create the plugin if required by calling LayoutPartForJSBindings.
@@ skipping 132 matching lines @@
 
 inline bool IsHTMLPlugInElement(const HTMLElement& element) {
   return element.IsPluginElement();
 }
 
 DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(HTMLPlugInElement);
 
 }  // namespace blink
 
 #endif  // HTMLPlugInElement_h