Handling text type errors
Handling text type errors

Summary:
public
Same tests failed due to text not being fully typed, but typing command is still 'marked' as success.
This diff switched typing to privte Apple's API to handle error case, that hopefuly will be raised.

Reviewed By: lawrencelomax

Differential Revision: D2839870

fb-gh-sync-id: ce25ee24de57bbb39632c3aad2133dfa1f1d4e88

riccoyu/WebDriverAgent,PiranhaTeam/WebDriverAgent,calabash/WebDriverAgent,b1ueshad0w/WebDriverAgent,zenzhu/WebDriverAgent,PiranhaTeam/WebDriverAgent,riccoyu/WebDriverAgent,Gogle/WebDriverAgent,rafael-chavez/WebDriverAgent,riccoyu/WebDriverAgent,ymin/WebDriverAgent,ymin/WebDriverAgent,truveris/WebDriverAgent,Gogle/WebDriverAgent,truveris/WebDriverAgent,zenzhu/WebDriverAgent,drptbl/WebDriverAgent,qa-dev/WebDriverAgent,PiranhaTeam/WebDriverAgent,rafael-chavez/WebDriverAgent,b1ueshad0w/WebDriverAgent,qa-dev/WebDriverAgent,b1ueshad0w/WebDriverAgent,qa-dev/WebDriverAgent,rafael-chavez/WebDriverAgent,truveris/WebDriverAgent,qa-dev/WebDriverAgent,PiranhaTeam/WebDriverAgent,ymin/WebDriverAgent,riccoyu/WebDriverAgent,calabash/WebDriverAgent,calabash/WebDriverAgent,PiranhaTeam/WebDriverAgent,ymin/WebDriverAgent,b1ueshad0w/WebDriverAgent,Gogle/WebDriverAgent,Gogle/WebDriverAgent,truveris/WebDriverAgent,drptbl/WebDriverAgent,zenzhu/WebDriverAgent,drptbl/WebDriverAgent,truveris/WebDriverAgent