Rewrite the fast/css/css2-system-fonts.html test

Rewrite the fast/css/css2-system-fonts.html test

This patch makes the fast/css/css2-system-fonts.html explicit about the
font styles expected on each platform instead of just Mac.
It also converts the test to be text only as the style information is
now displayed in text format.

This change is in preparation for a refactor of system font handling.

BUG=353932
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169612

[Timothy Loh, 2014-03-20 00:15:22]

lgtm

[alancutter (OOO until 2018), 2014-03-20 01:14:29]

The CQ bit was checked by alancutter@chromium.org

[commit-bot: I haz the power, 2014-03-20 01:14:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/alancutter@chromium.org/204113007/20001

[commit-bot: I haz the power, 2014-03-20 01:45:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-20 01:45:47]

Try jobs failed on following builders:
  tryserver.blink on win_blink_rel

[alancutter (OOO until 2018), 2014-03-20 02:27:58]

The CQ bit was checked by alancutter@chromium.org

[commit-bot: I haz the power, 2014-03-20 02:28:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/alancutter@chromium.org/204113007/20001

[commit-bot: I haz the power, 2014-03-20 04:06:01]

Change committed as 169612