Remove didChangeValueInTextField(HTMLInputElement&) and textFieldDidChange(const WebInputElement&)

The argument for these functions have been replaced by HTMLFormControlElement. Since changes at
both chromium and blink sides are landed, it's safe to remove these functions.

R=isherman@chromium.org, tkent@chromium.org
BUG=332557

Review URL: https://codereview.chromium.org/203263004

git-svn-id: svn://svn.chromium.org/blink/trunk@169983 bbb929c8-8fbe-4397-9dbb-9b2b20218538