Create pulseaudio upstart job, and add default client configurations + startup volume.

src/platform/init/windowmanager.conf

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 description   "Run the window manager for the given logged in user"
 author        "chromium-os-dev@chromium.org"
 
 # start-user-session is only emitted from the new session_manager code.
 # chromeos-xsession (the old way of starting the WM) is not run on that
 # code pathway.
 start on start-user-session
 stop on stopping ui
 
 # sadly, these can't reference each other.
 env DATA_DIR=/home/chronos
 env HOME=/home/chronos/user
 env XAUTHORITY=/home/chronos/.Xauthority
 env DISPLAY=:0.0
 
 # might be overridden by --uid parameter in /sbin/session_manager_setup.sh
 env USER_ID=1000
 
+env PULSE_RUNTIME_PATH=/var/run/pulse
+
 respawn
 script
 
 WM="/usr/bin/chromeos-wm"
 IMAGES="/usr/share/chromeos-assets/images"
 BACKGROUND_FILE="background_1024x600.png"
 BACKGROUND="${IMAGES}/${BACKGROUND_FILE}"
 LOG_DIR="${HOME}/log"
 XTERM_COMMAND="/usr/bin/xterm -bg black -fg grey +sb"
 
 cd ${HOME}
 exec /sbin/minijail --uid=${USER_ID} --                                   \
   "${WM}"                                                                 \
     --hotkey_overlay_image_dir="${IMAGES}"                                \
     --lm_overview_gradient_image="${IMAGES}/window_overview_gradient.png" \
     --log_dir="${LOG_DIR}"                                                \
     --panel_anchor_image="${IMAGES}/panel_anchor.png"                     \
     --panel_dock_background_image="${IMAGES}/panel_dock_bg.png"           \
     --shadow_image_dir="${IMAGES}"                                        \
     --wm_background_image="${BACKGROUND}"                                 \
     --wm_xterm_command="${XTERM_COMMAND}"
 end script