GTTF: Move logic related to "what to do next" out of TestResultsTracker

This is a preparation for making TestLauncher retry tests.

BUG=236893
R=sky@chromium.org

Review URL: https://codereview.chromium.org/29733004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229850 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229850
Don't hard-code python path.

Recently upgraded Macs have Python 2.7 in /usr/local/bin and the
hard-coded path is breaking the compile step.

R=maruel@chromium.org, mark@chromium.org
BUG=304948

Review URL: https://codereview.chromium.org/32843003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229854 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229854