Cherry pick HarfBuzz reverse_range fix

Cherry pick HarfBuzz reverse_range fix

Cherry pick the HarfBuzz commit 8ac345e5c0ed0aad6547592ea0839aabfb4ba980
as it fixes a set of serious shaping regressions in the core text shaper
on Mac OS. Cherry picking as opposed to rolling to allow for a clean DI.

BUG=459043
TBR=behdad@chromium.org

Committed: https://crrev.com/36504aa38b58939d103253524f2b9620ce998507
Cr-Commit-Position: refs/heads/master@{#318901}

[behdad_google, 2015-03-03 01:55:16]

behdad@google.com changed reviewers:
+ behdad@google.com

[behdad_google, 2015-03-03 01:55:17]

lgtm

[eae, 2015-03-03 16:33:15]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2015-03-03 16:34:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/971153002/1

[commit-bot: I haz the power, 2015-03-03 16:34:20]

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

[commit-bot: I haz the power, 2015-03-03 16:34:21]

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,
_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.

[eae, 2015-03-03 16:51:09]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2015-03-03 16:51:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/971153002/1

[commit-bot: I haz the power, 2015-03-03 17:35:10]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-03 17:35:57]

Patchset 1 (id:??) landed as
https://crrev.com/36504aa38b58939d103253524f2b9620ce998507
Cr-Commit-Position: refs/heads/master@{#318901}

[behdad_google, 2015-03-04 18:40:47]

lgtm