Update initial border style of <textaera> and <select> for non-Mac.

Use solid #a9a9a9 borders. This matches the native theme.  This border
style affects <textarea> and <select> elmeents only if they have
author styles and we don't use the native theme. This CL needs to
update a lot of rendering tests though the new border is not rendered.

BUG=332311
TEST=automated

Review URL: https://codereview.chromium.org/136643005

git-svn-id: svn://svn.chromium.org/blink/trunk@166363 bbb929c8-8fbe-4397-9dbb-9b2b20218538