[chromedriver] Mark step as failed if ant or java is not found  and disable some flaky tests.

BUG=None
NOTRY=true

Review URL: https://codereview.chromium.org/99193006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240221 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240221