Viewport lost "default" keyword, but is it still needed?

• Component: WebCore Misc.
• Status: NEW ---

[Joseph Pecoraro]

In the past, a valid keyword for viewport value was "default". This would
become the webkit client's default value for the given viewport key, similar
to "auto" when the value is undefined.

I don't think this concept is mentioned in the "css-viewport" spec, but this is a
regression from former behavior and functionality:
http://people.opera.com/rune/TR/css-viewport/

I'm still trying to work out whether or not it needs a new "ValueDefault"
enum value, or if "default" is just a way to explicitly say "ValueAuto".
Also, is this even necessary anymore? It seems as if web content
wants to dynamically change its viewport, it should just set the <meta>
tag again, and that will entirely replace the old viewport settings.