Add an extra guard to replaceDocument()

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 51a4731eaa7ea04fe6aef7e3b0d60af71509fdfd..252b355014a5eb05b7ec6ff1d5997c01d03c2d6b 100644
--- a/Source/core/dom/DocumentParser.h
+++ b/Source/core/dom/DocumentParser.h
@@ -58,7 +58,7 @@ public:
     // pinToMainThread also makes append() not yield before completion of that chunk.
     virtual void pinToMainThread() { }
 
-    // FIXME: append() should be private, but DocumentWriter::replaceDocument uses it for now.
+    // FIXME: append() should be private, but DocumentWriter::replaceDocumentWhileExecutingJavaScriptURL uses it for now.
     // FIXME: This really should take a PassOwnPtr to signify that it expects to take
     // ownership of the buffer. The parser expects the PassRefPtr to hold the only ref of the StringImpl.
     virtual void append(PassRefPtr<StringImpl>) = 0;