Pull buildtools.

This is to get update to checkdeps to update tree walking to not update a list while iterating over it.

TBR=qsr

Review URL: https://codereview.chromium.org/379923006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282151 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -73,7 +73,7 @@ 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": "916ba1fc49098855f8ddd08edd41484d36d84e08",
+  "buildtools_revision": "8e5430c72df4f1482eb8cae5cdb9fe963d5a50c4",
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFIum
   # and whatever else without interference from each other.