Fix unsafe shape_plan->face dependency

Fix unsafe shape_plan->face dependency

This cherry-picks http://cgit.freedesktop.org/harfbuzz/commit/src?id=f47b9219546edcfdeb3991ee27f6d9ba455c3e08

BUG=335156
TBR=eae@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=257509

[Xianzhu, 2014-03-17 17:14:08]

The update from 0.9.24 -> 0.9.26 broke some layout tests. I've reverted the
update and would like to leave the work to you harfbuzz experts.

The bug is M-33. We need a simple patch so that we can merge.

[behdad, 2014-03-17 17:34:23]

lgtm

[Xianzhu, 2014-03-17 17:44:04]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-03-17 17:44:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/202083003/1

[commit-bot: I haz the power, 2014-03-17 17:44:43]

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

[commit-bot: I haz the power, 2014-03-17 17:44:43]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Xianzhu, 2014-03-17 18:00:59]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-03-17 18:02:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/202083003/1

[commit-bot: I haz the power, 2014-03-17 18:04:00]

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

[commit-bot: I haz the power, 2014-03-17 18:04:01]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_rel

[Xianzhu, 2014-03-17 18:07:45]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-03-17 18:08:46]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/202083003/1

[commit-bot: I haz the power, 2014-03-17 18:12:03]

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

[commit-bot: I haz the power, 2014-03-17 18:12:04]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_chromeos_clang_dbg
  tryserver.chromium on linux_chromium_chromeos_rel
  tryserver.chromium on linux_chromium_clang_dbg
  tryserver.chromium on linux_chromium_rel
  tryserver.chromium on mac_chromium_compile_dbg
  tryserver.chromium on mac_chromium_rel
  tryserver.chromium on win_chromium_compile_dbg

[Xianzhu, 2014-03-17 18:20:40]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-03-17 18:21:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/202083003/1

[commit-bot: I haz the power, 2014-03-17 19:46:42]

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

[commit-bot: I haz the power, 2014-03-17 19:46:42]

Try jobs failed on following builders:
  tryserver.chromium on linux_chromium_chromeos_rel

[Xianzhu, 2014-03-17 20:14:46]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-03-17 20:15:53]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/202083003/1

[commit-bot: I haz the power, 2014-03-17 23:00:23]

Change committed as 257509

[eae, 2014-03-17 23:11:28]

LGTM (post-facto)