GTTF: instantiate ThreadChecker early in the test launcher

This makes sure it's also available during destructions.

While the immediate problem happened only with ParallelTestLauncher,
I'm proactively fixing similar pattern in other places.

BUG=236893
R=sky@chromium.org

Review URL: https://codereview.chromium.org/24398002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224838 0039d316-1c4b-4281-b951-d872f2087c98
[ispy] Move files from ispy/ispy_core/ to ispy/

BUG=297210
TEST=None
NOTRY=True

Review URL: https://chromiumcodereview.appspot.com/24217006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224840 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224840