Remove pulse audio env variable.
Remove pulse audio env variable.

Change-Id: I750bf1fe407e844ea97c7d271363b46b655afda8

BUG=None.
TEST=The window manager should still work fine after that change.

Review URL: http://codereview.chromium.org/6812024

joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager,joshfire/chromiumos-platform-window_manager