Add Windows on Swarm usage for the Chromium CQ.

It took a long time but Windows is now stable enough to be used by the CQ.
Fallbacks are still using non-Swarm jobs as a safety precaution.

Linux was added in r232775.
OSX was added in r234506.

R=phajdan.jr@chromium.org
BUG=

Review URL: https://codereview.chromium.org/105823014

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/commit-queue@241387 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed