Show or hide the elm_naviframe when is called ewk_view_visibility_set()

Show or hide the elm_naviframe when is called ewk_view_visibility_set()

If ewk_view_visibility_set() is called, white screen is shown in mobile.
Since background of elm_naviframe is white, white screen is appear.
When ewk_view_visiblity_set() is called,
elm_naviframe needs shown or hidden.

This patch brought in M42 (http://165.213.202.130/gerrit/#/c/88300/).

Reviewed by: a1.gomes, djmix.kim, msu.koo

Change-Id: I2ae719a8d563c7732a9ba3769e22f1780e8613fb
Signed-off-by: ByungJun Kim <bj1987.kim@samsung.com>