Store the Document's encoding on the Document

Source/core/rendering/RenderText.cpp

Index: Source/core/rendering/RenderText.cpp
diff --git a/Source/core/rendering/RenderText.cpp b/Source/core/rendering/RenderText.cpp
index 9572f74d5fed41be88aef11921c4f3c2181ceb15..d7a4fa64ab6da7ef071caec093fad66f55342651 100644
--- a/Source/core/rendering/RenderText.cpp
+++ b/Source/core/rendering/RenderText.cpp
@@ -186,7 +186,7 @@ bool RenderText::isWordBreak() const
 
 void RenderText::updateNeedsTranscoding()
 {
-    const WTF::TextEncoding* encoding = document()->decoder() ? &document()->decoder()->encoding() : 0;
+    const WTF::TextEncoding* encoding = document()->encoding().isValid() ? &document()->encoding() : 0;
     m_needsTranscoding = fontTranscoder().needsTranscoding(style()->font().fontDescription(), encoding);
 }
 
@@ -1329,7 +1329,7 @@ void RenderText::setTextInternal(PassRefPtr<StringImpl> text)
     ASSERT(text);
     m_text = text;
     if (m_needsTranscoding) {
-        const WTF::TextEncoding* encoding = document()->decoder() ? &document()->decoder()->encoding() : 0;
+        const WTF::TextEncoding* encoding = document()->encoding().isValid() ? &document()->encoding() : 0;
         fontTranscoder().convert(m_text, style()->font().fontDescription(), encoding);
     }
     ASSERT(m_text);