Remove moveCaretSelectionTowardsWindowPoint() (deprecated) from WebFrame API.

Chromium side was landed at:
https://src.chromium.org/viewvc/chrome?view=rev&revision=237476

Blink side was landed at:
https://src.chromium.org/viewvc/blink?view=rev&revision=162714

BUG=None
TEST=None
R=jamesr@chromium.org

Review URL: https://codereview.chromium.org/95613003

git-svn-id: svn://svn.chromium.org/blink/trunk@163028 bbb929c8-8fbe-4397-9dbb-9b2b20218538