Mac: Fix fallback font selection for custom fonts

Mac: Fix fallback font selection for custom fonts

This fixes a bug where a bullet character (U+25CF) becomes tofu when it
is a fallback for a webfont and italic style. The fallback font
(Helvetica) has a glyph for U+25CF, but its italic variation (Helvetica
Oblique) does not. In such a case, we should use synthetic oblique.

BUG=373389
TEST=fast/text/fallback-for-custom-font.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175243

[eae, 2014-05-29 20:53:33]

LGTM

[eae, 2014-05-29 20:53:38]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2014-05-29 20:56:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ksakamoto@chromium.org/300393003/40001

[Kunihiko Sakamoto, 2014-05-30 03:34:55]

The CQ bit was unchecked by ksakamoto@chromium.org

[Kunihiko Sakamoto, 2014-05-30 03:39:16]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2014-05-30 03:41:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ksakamoto@chromium.org/300393003/60001

[commit-bot: I haz the power, 2014-05-30 10:17:17]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/9582)

[commit-bot: I haz the power, 2014-05-30 11:02:32]

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

[commit-bot: I haz the power, 2014-05-30 11:02:33]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/9582)

[Kunihiko Sakamoto, 2014-06-02 01:09:43]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2014-06-02 01:09:50]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ksakamoto@chromium.org/300393003/60001

[commit-bot: I haz the power, 2014-06-02 01:42:58]

Change committed as 175243