Started packaging: https://codereview.chromium.org/1957703003

https://codereview.chromium.org/1953343002 for r268784, a windows fix

https://codereview.chromium.org/1950303005 for 268794 and 268797

https://codereview.chromium.org/1959613003 for 268799

268791 broke several tests on windows (see http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/11993) so we need a fix for that first. zturner's looking at it.

https://codereview.chromium.org/1956983002 for zturner's fix in r268813

started goma push of that, heading home now

goma is ready, started tryjobs

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/daae653a39fe75fc4b5e73fddf2c8909a9566074

commit daae653a39fe75fc4b5e73fddf2c8909a9566074
Author: hans <hans@chromium.org>
Date: Sat May 07 04:55:12 2016

Roll clang 268419:268813.

Includes a fix for crashes in TSan builds, such as
https://bugs.chromium.org/p/v8/issues/detail?id=4995

BUG= 609947 

Review-Url: https://codereview.chromium.org/1956983002
Cr-Commit-Position: refs/heads/master@{#392245}

[modify] https://crrev.com/daae653a39fe75fc4b5e73fddf2c8909a9566074/tools/clang/scripts/update.py