Add preliminary support for UBSan in Chromium.

Add preliminary support for UBSan in Chromium.
Right now ubsan=1 doesn't work with Chromium-packaged Clang because of missing libraries.

BUG=174801
R=thakis@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=273944

[Alexander Potapenko, 2014-05-27 15:12:41]

PTAL

[Nico, 2014-05-27 15:17:33]

woot! lgtm

[Alexander Potapenko, 2014-05-27 15:18:44]

The CQ bit was checked by glider@chromium.org

[commit-bot: I haz the power, 2014-05-27 15:19:17]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/glider@chromium.org/299403007/1

[commit-bot: I haz the power, 2014-05-27 17:10:18]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_aosp on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_aosp/builds/7...)
  android_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_clang_dbg/bui...)
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/18...)
  linux_chromium_chromeos_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_chromeos_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_clang_...)
  linux_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_rel/bu...)
  linux_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/linux_gpu/builds/...)

[commit-bot: I haz the power, 2014-05-27 17:13:32]

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

[commit-bot: I haz the power, 2014-05-27 17:13:33]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_chrome...)
  linux_chromium_clang_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/linux_chromium_clang_...)

[Alexander Potapenko, 2014-05-30 15:17:38]

The CQ bit was checked by glider@chromium.org

[commit-bot: I haz the power, 2014-05-30 15:19:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/glider@chromium.org/299403007/20001

[commit-bot: I haz the power, 2014-05-30 19:16:56]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg/builds/19...)
  mac_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/mac_chromium_rel/buil...)

[commit-bot: I haz the power, 2014-05-30 23:59:07]

Change committed as 273944