Remove the Document.charset setter (making it readonly)

Source/core/loader/DocumentLoader.cpp

Index: Source/core/loader/DocumentLoader.cpp
diff --git a/Source/core/loader/DocumentLoader.cpp b/Source/core/loader/DocumentLoader.cpp
index 2980d06430868e997411ceecb1faefb3e8d36ec6..a7cefb67954b51ed7de97528dc42e5c037dd7d3f 100644
--- a/Source/core/loader/DocumentLoader.cpp
+++ b/Source/core/loader/DocumentLoader.cpp
@@ -766,12 +766,6 @@ const AtomicString& DocumentLoader::mimeType() const
     return m_response.mimeType();
 }
 
-void DocumentLoader::setUserChosenEncoding(const String& charset)
-{
-    if (m_writer)
-        m_writer->setUserChosenEncoding(charset);
-}
-
 // This is only called by FrameLoader::replaceDocumentWhileExecutingJavaScriptURL()
 void DocumentLoader::replaceDocumentWhileExecutingJavaScriptURL(const DocumentInit& init, const String& source, Document* ownerDocument)
 {