Remove all support for <applet> handling in Chrome.

Source/core/layout/LayoutPart.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. 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
@@ skipping 78 matching lines @@
     deref();
 }
 
 LayoutPart::~LayoutPart()
 {
     ASSERT(m_refCount <= 0);
 }
 
 Widget* LayoutPart::widget() const
 {
-    // Plugin widgets are stored in their DOM node. This includes HTMLAppletElement.
+    // Plugin widgets are stored in their DOM node.
     Element* element = toElement(node());
 
     if (element && element->isFrameOwnerElement())
         return toHTMLFrameOwnerElement(element)->ownedWidget();
 
     return nullptr;
 }
 
 DeprecatedPaintLayerType LayoutPart::layerTypeRequired() const
 {
@@ skipping 228 matching lines @@
     if (widget() && widget()->isFrameView()) {
         FrameView* childFrameView = toFrameView(widget());
         PaintInvalidationState childViewPaintInvalidationState(*childFrameView->layoutView(), paintInvalidationState);
         toFrameView(widget())->invalidateTreeIfNeeded(childViewPaintInvalidationState);
     }
 
     LayoutReplaced::invalidatePaintOfSubtreesIfNeeded(paintInvalidationState);
 }
 
 }