Bug 945222 - Update web-platform-tests to revision 12708681a936856c1730d990adf7c5e108928e83
Update wptrunner.
Bug 945222 - Update web-platform-tests to revision 2ce2e35f947be48fdfca570cfc2ae6277b7e1479

--HG--
rename : testing/web-platform/tests/ambient-light/DeviceLight_tests.html => testing/web-platform/tests/ambient-light/AmbientLight_tests.html
rename : testing/web-platform/tests/ambient-light/DeviceLight_tests.js => testing/web-platform/tests/ambient-light/DeviceLightEvent_tests.js