[webkit-efl] I'd like to refactor zoom related APIs.

[Ryuan Choi]

> I think scale_set can be replaced zoom_set. But, I'm not sure if scale_set
> is more clear than zoom_set for users.

scale_set doesn't replace zoom_set, but ewk_view_zoom_set lost functionality of center zoom.
This patch provide three different zoom feature, scale_set and zoom_set and text_zoom_set.

But, as we discussed in private channel, scale_set and zoom_set is still confused.
So, How do you think about ewk_{frame|view}_page_zoom_set instead of ewk_{frame|view}_zoom_set ?

> In addition, it looks gtk and qt port still use zoom instead scale term.

IIRC, gtk doesn't support scalePage feature yet. you can find it from WebKit2.

Best Regards,
Ryuan Choi