Revert "Temporarily disabling AppRTC on win and mac until
we can fix the windows bots and figure out why it breaks
on mac."

The bot config should be OK now for the AppRTC test.
The mac issue is likely due to
https://code.google.com/p/webrtc/issues/detail?id=1742,
e.g. a bug in apprtc.

BUG=303021
TBR=xians@chromium.org

Review URL: https://codereview.chromium.org/35233003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230136 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230136