Added a URL type to iOS.
Added a URL type to iOS.

This allows native identity to return to the app after the user authenticates.

MobileChromeApps/mobile-chrome-apps,chirilo/mobile-chrome-apps,hgl888/mobile-chrome-apps,wudkj/mobile-chrome-apps,xiaoyanit/mobile-chrome-apps,xiaoyanit/mobile-chrome-apps,wudkj/mobile-chrome-apps,MobileChromeApps/mobile-chrome-apps,xiaoyanit/mobile-chrome-apps,guozanhua/mobile-chrome-apps,liqingzhu/mobile-chrome-apps,liqingzhu/mobile-chrome-apps,chirilo/mobile-chrome-apps,hgl888/mobile-chrome-apps,wudkj/mobile-chrome-apps,liqingzhu/mobile-chrome-apps,guozanhua/mobile-chrome-apps,chirilo/mobile-chrome-apps,wudkj/mobile-chrome-apps,guozanhua/mobile-chrome-apps,hgl888/mobile-chrome-apps,MobileChromeApps/mobile-chrome-apps,hgl888/mobile-chrome-apps,MobileChromeApps/mobile-chrome-apps,guozanhua/mobile-chrome-apps,chirilo/mobile-chrome-apps,hgl888/mobile-chrome-apps,hgl888/mobile-chrome-apps,xiaoyanit/mobile-chrome-apps,hgl888/mobile-chrome-apps,liqingzhu/mobile-chrome-apps