Additional items added to selection services menus are misaligned

Additional items added to selection services menus are misaligned
https://bugs.webkit.org/show_bug.cgi?id=135747
<rdar://problem/17933167>

Reviewed by Brady Eidson.

* UIProcess/mac/WebContextMenuProxyMac.mm:
(WebKit::WebContextMenuProxyMac::setupServicesMenu):
Use NSSharingServicePickerStyleRollover for the rollover image services menu;
use NSSharingServicePickerStyleTextSelection for the selection services menu.

Set NSMenu's showsStateColumn to YES for selection services menus, so that
other items added to the menu line up correctly.

Remove an unncessary .get()

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@172343 268f45cc-cd09-0410-ab3c-d52691b4dbfc