Use CheckCallAndFilterAndHeader for git commands.

Use CheckCallAndFilterAndHeader for git commands.

This causes git commands to be completely silent (they don't even print
______ running 'git foo bar') if the git command itself is completely silent.
This mirrors the behavior of SVN commands. This is useful for commands like
'gclient diff', which should print no output at all if there is no diff.

R=szager@chromium.org, vadimsh@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=260758

[iannucci, 2014-04-01 02:29:00]

*sigh* lgtm

[agable, 2014-04-01 02:33:41]

Stefan: landing this is necessary for switching the commit queue to git. There
are other ways to fix it (such as making the commit queue willing to accept
output when it runs 'gclient diff') but I think this is the Right Way to fix it.
I went through all the test cases by hand and they make sense. Please let me
know if you think this breaks something and I'll revert and take another route.

[agable, 2014-04-01 02:33:53]

The CQ bit was checked by agable@chromium.org

[commit-bot: I haz the power, 2014-04-01 02:33:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/agable@chromium.org/218993009/20001

[commit-bot: I haz the power, 2014-04-01 02:35:45]

Change committed as 260758

[szager1, 2014-04-02 17:19:45]

lgtm, I always hated that terminal spew.