Remove custom style building for font-variant-ligatures.

Remove custom style building for font-variant-ligatures.

This patch uses a small, in-flight structure 'VariantLigatures' to
transfer the font-variant-ligatures data during style building.

This makes font style building less custom, and it removes some use of
CSSValue inside FontBuilder.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179588

[dglazkov, 2014-08-05 14:59:51]

LGTM!

[andersr, 2014-08-05 18:21:10]

The CQ bit was checked by andersr@opera.com

[commit-bot: I haz the power, 2014-08-05 18:23:42]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/andersr@opera.com/447443003/1

[commit-bot: I haz the power, 2014-08-06 00:06:23]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/android_blink_compile_db...)
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/1...)
  linux_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/1...)
  mac_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_compile_dbg/bu...)
  win_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_compile_dbg/bu...)

[commit-bot: I haz the power, 2014-08-06 00:51:09]

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

[commit-bot: I haz the power, 2014-08-06 00:51:10]

Try jobs failed on following builders:
  win_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_compile_dbg/bu...)

[andersr, 2014-08-06 07:41:15]

The CQ bit was checked by andersr@opera.com

[commit-bot: I haz the power, 2014-08-06 07:41:27]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/andersr@opera.com/447443003/1

[commit-bot: I haz the power, 2014-08-06 08:42:15]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_compile_dbg/bu...)

[commit-bot: I haz the power, 2014-08-06 09:09:45]

Change committed as 179588