Move 'designMode' attribute from HTMLDocument to Document

Source/core/html/HTMLDocument.cpp

Index: Source/core/html/HTMLDocument.cpp
diff --git a/Source/core/html/HTMLDocument.cpp b/Source/core/html/HTMLDocument.cpp
index 95fa689165c2e06c66e53588b483a558f8030d80..2ed399905787be91dcff354bb2b90e5d82d4a8b2 100644
--- a/Source/core/html/HTMLDocument.cpp
+++ b/Source/core/html/HTMLDocument.cpp
@@ -79,23 +79,6 @@ HTMLDocument::~HTMLDocument()
 {
 }
 
-String HTMLDocument::designMode() const
-{
-    return inDesignMode() ? "on" : "off";
-}
-
-void HTMLDocument::setDesignMode(const String& value)
-{
-    InheritedBool mode;
-    if (equalIgnoringCase(value, "on"))
-        mode = on;
-    else if (equalIgnoringCase(value, "off"))
-        mode = off;
-    else
-        mode = inherit;
-    Document::setDesignMode(mode);
-}
-
 HTMLBodyElement* HTMLDocument::htmlBodyElement() const
 {
     HTMLElement* body = this->body();