Don't try to send automation message after the corresponding RV is gone

BUG=none
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/133403003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244489 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244489
Docserver: Support markdown for HTML content. Request thirdparty submission review.

R=kalman@chromium.org
BUG=293681

Review URL: https://codereview.chromium.org/133433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244490 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244490