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

Source/core/dom/StyleElement.h

Index: Source/core/dom/StyleElement.h
diff --git a/Source/core/dom/StyleElement.h b/Source/core/dom/StyleElement.h
index 7949fc465f9cd7c80e423389b93c5afc45dc015e..45d8b00cf880abd981b6c4597a389ade4ba2b670 100644
--- a/Source/core/dom/StyleElement.h
+++ b/Source/core/dom/StyleElement.h
@@ -54,6 +54,10 @@ protected:
     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:
@@ -65,6 +69,7 @@ private:
     bool m_loading : 1;
     bool m_registeredAsCandidate : 1;
     TextPosition m_startPosition;
+    String m_whitelistedSource;
 };
 
 }