Revert "Mark parsing routines with ENABLE(SVG_FONTS)"

This reverts commit aae7e46b456aeb3c880a13a5568ffa772cdd6171.

Breaks webkit_tests svg/custom/svg-fonts-without-missing-glyph.xhtml
on WebKit XP

BUG=242735
TBR=tkent,rob.buis@samsung.com,pdr

Review URL: https://codereview.chromium.org/541023002

git-svn-id: svn://svn.chromium.org/blink/trunk@181387 bbb929c8-8fbe-4397-9dbb-9b2b20218538