Update expected result of fast/events/key-events-in-input-button.html and temporarily
disable this test until https://codereview.chromium.org/649343002 has landed.

BUG=423270
NOTRY=true
TBR=abarth@chromium.org

Review URL: https://codereview.chromium.org/641233004

git-svn-id: svn://svn.chromium.org/blink/trunk@184762 bbb929c8-8fbe-4397-9dbb-9b2b20218538