DocumentParser should flush itself on finish

Source/core/dom/DocumentParser.h

Index: Source/core/dom/DocumentParser.h
diff --git a/Source/core/dom/DocumentParser.h b/Source/core/dom/DocumentParser.h
index 83de2a4c95d46b014425dfdca6c1882c476df7b2..51a4731eaa7ea04fe6aef7e3b0d60af71509fdfd 100644
--- a/Source/core/dom/DocumentParser.h
+++ b/Source/core/dom/DocumentParser.h
@@ -50,7 +50,6 @@ public:
 
     // The below functions are used by DocumentWriter (the loader).
     virtual void appendBytes(const char* bytes, size_t length) = 0;
-    virtual void flush() = 0;
     virtual bool needsDecoder() const { return false; }
     virtual void setDecoder(PassOwnPtr<TextResourceDecoder>);
     virtual TextResourceDecoder* decoder();
@@ -107,6 +106,8 @@ public:
 protected:
     explicit DocumentParser(Document*);
 
+    virtual void flush() = 0;
+
 private:
     enum ParserState {
         ParsingState,