Do not call moveCaretSelectionTowardsWindowPoint() (deprecated).

Instead just call moveCaretSelection() which seems to be the
recommended, non-deprecated version.

BUG=None
TEST=webkit_unit_tests
--gtest_filter=WebFrameTest.MoveCaretStaysHorizontallyAlignedWhenMoved
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/83043008

git-svn-id: svn://svn.chromium.org/blink/trunk@162714 bbb929c8-8fbe-4397-9dbb-9b2b20218538