The tests now base the directory in mkdtemp() which is much safer than using the
source's file directory as before.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/6625018

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@77278 0039d316-1c4b-4281-b951-d872f2087c98