Move plugin placeholder style to CSS, and allow it to bypass main world CSP.

Source/core/dom/StyleElement.h

 /*
  * Copyright (C) 2006, 2007 Rob Buis
  *
  * 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 36 matching lines @@
     bool sheetLoaded(Document&);
     void startLoadingDynamicSheet(Document&);
 
     void processStyleSheet(Document&, Element*);
     void removedFromDocument(Document&, Element*);
     void removedFromDocument(Document&, Element*, ContainerNode* scopingNode, TreeScope&);
     void clearDocumentData(Document&, Element*);
     void childrenChanged(Element*);
     void finishParsingChildren(Element*);
 
+    // Authorized a particular string to be used, even if CSP does not permit
+    // inline style.
+    void whitelistSource(const String& source) { m_whitelistedSource = source; }
+
     RefPtrWillBeMember<CSSStyleSheet> m_sheet;
 
 private:
     void createSheet(Element*, const String& text = String());
     void process(Element*);
     void clearSheet(Element* ownerElement = 0);
 
     bool m_createdByParser : 1;
     bool m_loading : 1;
     bool m_registeredAsCandidate : 1;
     TextPosition m_startPosition;
+    String m_whitelistedSource;
 };
 
 }
 
 #endif