am 41773d46: Merge "DO NOT MERGE Revert "Revert "AudioFlinger: mix track only when really ready (2)""" into ics-mr1

* commit '41773d46556aa47d4322ff89fdaf7d1345c2d1f2':
  DO NOT MERGE Revert "Revert "AudioFlinger: mix track only when really ready (2)""