PulseAudio Sound Playback on Linux

This is the preliminary implementation of a PulseAudio sound backend for Chrome on Linux.  At first, PulseAudio's mainloop, mainloop_api, and context constructs will be used instead of the message loop system used in alsa_output.  This will be stereo only at first.  Also, at first, PulseAudio will be dynamically linked in media.gyp as opposed to the final solution which will dynamically link PulseAudio in runtime if it is available.

BUG=32757
TEST=


Review URL: http://codereview.chromium.org/7473021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@97408 0039d316-1c4b-4281-b951-d872f2087c98
8 files changed