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

Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.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
  * 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
@@ skipping 247 matching lines @@
 }
 
 void Page::refreshPlugins()
 {
     if (allPages().isEmpty())
         return;
 
     PluginData::refresh();
 
     for (const Page* page : allPages()) {
-        // Clear out the page's plug-in data.
+        // Clear out the page's plugin data.
         if (page->m_pluginData)
             page->m_pluginData = nullptr;
     }
 }
 
 PluginData* Page::pluginData() const
 {
     if (!mainFrame()->isLocalFrame()
         || !deprecatedLocalMainFrame()->loader().allowPlugins(NotAboutToInstantiatePlugin))
         return nullptr;
@@ skipping 342 matching lines @@
     , dragClient(nullptr)
     , spellCheckerClient(nullptr)
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 } // namespace blink