Previously we just added an assert here but better
to simply succeed in this case, while outputting
the intial failure message.

BUG=425696

Review URL: https://codereview.chromium.org/667793005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@292687 0039d316-1c4b-4281-b951-d872f2087c98