Remove Editor::setSelectionOffsets
https://bugs.webkit.org/show_bug.cgi?id=115831

Reviewed by Andreas Kling.

Removed the function added in r120985 for Chromium Android port.

* editing/Editor.cpp:
* editing/Editor.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149785 268f45cc-cd09-0410-ab3c-d52691b4dbfc