Remove WebInputElement.h includes from some autofill core unittests.

This also allow us to remove this entry from the DEPS file.

BUG=140037
TEST=unit_tests links
TBR=joi@chromium.org,blundell@chromium.org

Review URL: https://codereview.chromium.org/145123011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250019 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250019