Roll src/buildtools/ 13a00f110..da9b2941c (3 commits)

https://chromium.googlesource.com/chromium/buildtools.git/+log/13a00f110ef9..da9b2941cbf6

$ git log 13a00f110..da9b2941c --date=short --no-merges --format='%ad %ae %s'
2018-11-20 thakis Revert "Roll libcxx{abi}
2018-11-16 smaier Update clang-format binaries and scripts for all platforms.
2018-10-29 thomasanderson Roll libcxx{abi}

Created with:
  roll-dep src/buildtools

Bug: 768586,768983
Change-Id: Ib72e2e4f38b9ed662652a440925ff9260f97abcc
Reviewed-on: https://chromium-review.googlesource.com/c/1344293Reviewed-by: Sam Maier <smaier@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609898}

DEPS

@@ -128,7 +128,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.
-  'buildtools_revision': '13a00f110ef910a25763346d6538b60f12845656',
+  'buildtools_revision': 'da9b2941cbf6d6d67b694e069e8e8dc06910f66a',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.