Re-land "Merge HarfBuzz kerning support from Blink"

Re-land "Merge HarfBuzz kerning support from Blink"

> Merge HarfBuzz kerning support from Blink
>
> Original CL: https://codereview.chromium.org/69513002
>
> BUG=321868
> R=msw@chromium.org
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=273181

BUG=321868
R=msw@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=273727

[msw, 2014-05-29 18:35:42]

lgtm, but for future reference it's nice to upload the original CL as the first
patch set, then make corrections, so reviewers can easily see the changes made
to address the cause for revert.

[ckocagil, 2014-05-29 20:45:09]

The CQ bit was checked by ckocagil@chromium.org

[commit-bot: I haz the power, 2014-05-29 20:46:53]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/ckocagil@chromium.org/308433003/1

[commit-bot: I haz the power, 2014-05-30 00:36:32]

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

[commit-bot: I haz the power, 2014-05-30 05:32:44]

Change committed as 273727