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

Source/core/frame/DOMWindowPrivateScript.cpp

Index: Source/core/frame/DOMWindowPrivateScript.cpp
diff --git a/Source/platform/exported/WebSerializedOrigin.cpp b/Source/core/frame/DOMWindowPrivateScript.cpp
similarity index 51%
copy from Source/platform/exported/WebSerializedOrigin.cpp
copy to Source/core/frame/DOMWindowPrivateScript.cpp
index bc90296d55c3bf3b41553fc81434fd28adf6b4a9..f27f89dd9338f2af30f6a3a2b7fea7d1c1cae219 100644
--- a/Source/platform/exported/WebSerializedOrigin.cpp
+++ b/Source/core/frame/DOMWindowPrivateScript.cpp
@@ -3,15 +3,15 @@
 // found in the LICENSE file.
 
 #include "config.h"
-#include "public/platform/WebSerializedOrigin.h"
+#include "core/frame/DOMWindowPrivateScript.h"
 
-#include "platform/weborigin/SecurityOrigin.h"
+#include "platform/PlatformResourceLoader.h"
 
 namespace blink {
 
-WebSerializedOrigin::WebSerializedOrigin(const SecurityOrigin& origin)
-    : m_string(origin.toString())
+String DOMWindowPrivateScript::loadPlatformResource(const String& name)
 {
+    return loadResourceAsASCIIString(name.ascii().data());
 }
 
 } // namespace blink