Call XInitThreads on host startup

Call XInitThreads on host startup.

This is required in order for the host to be able to safely use X11
across multiple threads, e.g. for input-injection, screen capture and
any UX.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=290687

[Sergey Ulanov, 2014-08-19 19:44:41]

lgtm

[Wez, 2014-08-19 19:48:17]

The CQ bit was checked by wez@chromium.org

[commit-bot: I haz the power, 2014-08-19 19:49:41]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/wez@chromium.org/487453004/1

[commit-bot: I haz the power, 2014-08-19 21:22:49]

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

[commit-bot: I haz the power, 2014-08-19 21:33:56]

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

[commit-bot: I haz the power, 2014-08-19 21:33:56]

Try jobs failed on following builders:
  linux_chromium_rel_swarming on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Wez, 2014-08-19 21:44:35]

The CQ bit was checked by wez@chromium.org

[commit-bot: I haz the power, 2014-08-19 21:45:08]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/wez@chromium.org/487453004/20001

[commit-bot: I haz the power, 2014-08-19 22:59:30]

Committed patchset #2 (20001) as 290687