This is part of my intern project, which is detailed here:
  "https://docs.google.com/a/google.com/document/d/10bkzag1UUbtESPkEWHYaZtGMEEbCN5Zad72PuoRpwZE/edit#"

The idea is to have "git cl upload" annotate the CL description with a
flag like "CQ_TRYBOTS=...", which CQ will then look at to determine which
trybots to run the the given CL.

The CL for the change for CQ is at "https://chromereviews.googleplex.com/51757013/".

R=dpranke@google.com, iannucci@google.com
BUG=378097

Review URL: https://codereview.chromium.org/348473003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@280039 0039d316-1c4b-4281-b951-d872f2087c98