Would you accept to add new faces that could be useful to some major modes ?

I am thinking of 

font-lock-tag-name-face

font-lock-attr-name-face

font-lock-attr-value-face

and also

font-lock-symbol-face

I am the author of web-mode.el and think that inheriting from those faces would provide better defaults for users of those modes.

It would also ease the work of theme maintainers. 

fx