Bug 913241 - Support chunking mochitests from mach; r=jmaher
Bug 860839 - Initial implementation of |mach test|; r=jhammel

The future of running tests is this command. It is a unified command for
running tests. Currently, it only supports running test suites from
their full test suite name or TBPL abbreviation. Support will be added
in the future for running individual tests or mixing and matching tests
of different flavors.