Fixed the issue that Cordova demos cannot build
Fixed the issue that Cordova demos cannot build

Replace the WKWebView with XWalkView, due to the recent change of
the implementation.

BUG: https://crosswalk-project.org/jira/browse/XWALK-4476

ericzhou2008/crosswalk-ios,jondong/crosswalk-ios,RafuCater/crosswalk-ios,mattWillis/crosswalk-ios,jondong/crosswalk-ios,hgl888/crosswalk-ios,RafuCater/crosswalk-ios,crosswalk-project/crosswalk-ios,minggangw/crosswalk-ios,hgl888/crosswalk-ios,crosswalk-project/crosswalk-ios,hgl888/crosswalk-ios,negherbon/crosswalk-ios,ericzhou2008/crosswalk-ios,ericzhou2008/crosswalk-ios,jondong/crosswalk-ios,negherbon/crosswalk-ios,RafuCater/crosswalk-ios,hgl888/crosswalk-ios,minggangw/crosswalk-ios,minggangw/crosswalk-ios,negherbon/crosswalk-ios,mattWillis/crosswalk-ios,jondong/crosswalk-ios,ericzhou2008/crosswalk-ios,minggangw/crosswalk-ios,negherbon/crosswalk-ios,RafuCater/crosswalk-ios,mattWillis/crosswalk-ios,mattWillis/crosswalk-ios,crosswalk-project/crosswalk-ios,crosswalk-project/crosswalk-ios