Blink: Replace all "plug-in" with "plugin".

Source/core/layout/LayoutPart.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2006, 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.
  *
@@ skipping 11 matching lines @@
 
 #ifndef LayoutPart_h
 #define LayoutPart_h
 
 #include "core/CoreExport.h"
 #include "core/layout/LayoutReplaced.h"
 #include "platform/Widget.h"
 
 namespace blink {
 
-// Renderer for frames via LayoutFrame and LayoutIFrame, and plug-ins via LayoutEmbeddedObject.
+// Renderer for frames via LayoutFrame and LayoutIFrame, and plugins via LayoutEmbeddedObject.
 class CORE_EXPORT LayoutPart : public LayoutReplaced {
 public:
     explicit LayoutPart(Element*);
     virtual ~LayoutPart();
 
     bool requiresAcceleratedCompositing() const;
 
     virtual bool needsPreferredWidthsRecalculation() const override final;
 
     virtual bool nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
@@ skipping 30 matching lines @@
     bool nodeAtPointOverWidget(const HitTestRequest&, HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction);
 
     int m_refCount;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutPart, isLayoutPart());
 
 } // namespace blink
 
 #endif // LayoutPart_h