Remove guessesVector param from isUngrammatical
https://bugs.webkit.org/show_bug.cgi?id=119241

Reviewed by Ryosuke Niwa.

TextCheckingHelper::isUngrammatical(Vector<String>& guessesVector) doesn't return
guesses for ungrammatical phrases through its parameter.
Editor::isSelectionUngrammatical() uses it to check whether the selection
is ungrammatical.

r71009 showed that isUngrammatical(Vector<String>& guessesVector) had not supported
grammar guesses.

The grammar guesses can be retrieved by guessesForMisspelledOrUngrammaticalRange
when UNIFIED_TEXT_CHECKING is on.

No new tests, this is dead code due to no WebKit port implements grammar using
legacy text checker.

* WebCore.exp.in: Removed __ZN7WebCore6Editor32guessesForUngrammaticalSelectionEv.
* editing/Editor.cpp:
(WebCore::Editor::isSelectionUngrammatical):
(WebCore::Editor::guessesForMisspelledOrUngrammatical):
* editing/Editor.h: Removed guessesForUngrammaticalSelection. Dead code.
* editing/TextCheckingHelper.cpp:
(WebCore::TextCheckingHelper::isUngrammatical):
* editing/TextCheckingHelper.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153515 268f45cc-cd09-0410-ab3c-d52691b4dbfc