If the tree is closed then print information about contacting the sheriff.

The motivation for this CL is because it is not very obvious on how to submit when tree is closed in git.

Also added a section 'How to submit when tree is closed' in https://sites.google.com/site/skiadocs/developer-documentation/tree-sheriff

(SkipBuildbotRuns)
Review URL: https://codereview.chromium.org/13932026

git-svn-id: http://skia.googlecode.com/svn/trunk@8666 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed