Dispatch input event for Range element keyboard event

For any value update, dispatch both input and change event.

Also removes extra dispatch change event, as event are dispatch from TextFieldInputType:setValue.

R=tkent, keishi1
BUG=345611
TEST=On keyboard event, both oninput and onchange event are triggered

Review URL: https://codereview.chromium.org/178593003

git-svn-id: svn://svn.chromium.org/blink/trunk@168558 bbb929c8-8fbe-4397-9dbb-9b2b20218538