Oilpan: Prepare to move InputTypeView and InputType to Oilpan heap.

BUG=357163

Review URL: https://codereview.chromium.org/264383005

git-svn-id: svn://svn.chromium.org/blink/trunk@173498 bbb929c8-8fbe-4397-9dbb-9b2b20218538