This allows non-committers to use fetch to checkout chromium or blink using

$ fetch chromium --nosvn=true

BUG=230357
R=dpranke@chromium.org

Review URL: https://codereview.chromium.org/13910005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@193713 0039d316-1c4b-4281-b951-d872f2087c98