Remove 'alphabetic' value from text-underline-position

According to latest version of CSS3 Text Decoration W3C standard (W3C
Candidate Recommendation 1 August 2013), the text-underline-position
property does not include 'alphabetic' as valid property value, thus the
need to remove it from implementation.

David Baron's feedback on why removing this:
http://lists.w3.org/Archives/Public/www-style/2013Mar/0529.html

Specification link:
http://dev.w3.org/csswg/css-text-decor-3/#text-underline-position

BUG=311335

Review URL: https://codereview.chromium.org/57493002

git-svn-id: svn://svn.chromium.org/blink/trunk@161361 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove dead code, AXObject::page

I was looking for Page usages to remove
in preparation for more OOPI work, but this
code seems completely dead.

BUG=305811

Review URL: https://codereview.chromium.org/59403002

git-svn-id: svn://svn.chromium.org/blink/trunk@161362 bbb929c8-8fbe-4397-9dbb-9b2b20218538