Currently those two tests fail webaudio/audiobuffersource-loop-points.html failed unexpectedly (audio mismatch) webaudio/audiobuffersource-playbackrate.html failed unexpectedly (audio mismatch) The first one seems to be only related to rounding, in that sense similar to bug 105291, the second one has bigger difference.
It seems something is not cleaned up properly. run-webkit-tests --gtk -v --child-processes=1 --run-singly webaudio/audiobuffersource-loop-comprehensive.html webaudio/audiobuffersource-channels.html works run-webkit-tests --gtk -v --child-processes=1 webaudio/audiobuffersource-loop-comprehensive.html webaudio/audiobuffersource-channels.html webaudio/audiobuffersource-loop-comprehensive.html times out if it runs after webaudio/audiobuffersource-channels.html.