Added unprefixed version of Touch radius and force

Adding unprefixed version of Touch radius and force.
https://groups.google.com/a/chromium.org/d/msg/blink-dev/rjLM4KvRrjk/LnEHWYLZE8MJ

BUG=378780

Review URL: https://codereview.chromium.org/335413003

git-svn-id: svn://svn.chromium.org/blink/trunk@176909 bbb929c8-8fbe-4397-9dbb-9b2b20218538