No GitPoller on non-production host for libvpx.
No GitPoller on non-production host for libvpx.

This fixes presubmit on mac hosts.

BUG=349092

Review URL: https://codereview.chromium.org/183923028

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@254899 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build