Add a hack to deal with needing to spawn pulseaudio, and deal with the changes HOME of chronos.

src/platform/acpi/action_hotkey.sh

 #!/bin/sh
 
 # Copyright (c) 2009 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.
 
 # TODO: This is specific to eeepc. Figure out a way to generalize and
 # add support for additional hotkeys.
+#
+# TODO(ajwong): Find a better way to talk to pulseaudio than changing to the
+# chronos user and talking to pulseaudio via amixer.
+
+USER_ID="$(/usr/bin/id -u chronos)"
+MINIJAIL_FLAGS="--use-capabilities"
+
+# Needed by amixer to so that the alsa pulseaudio plugin, can locate the
+# correct ${HOME}/.pulse directory.
+export HOME=/home/chronos/user
 
 case "$3" in
   00000013)  # Toggle sound
-        amixer set Master toggle
+        /sbin/minijail ${MINIJAIL_FLAGS} --uid=${USER_ID} -- \
+            /usr/bin/amixer set Master toggle
         ;;
   00000014)  # Decrease volume
-        amixer set Master 5%-
+        /sbin/minijail ${MINIJAIL_FLAGS} --uid=${USER_ID} -- \
+            /usr/bin/amixer set Master 5%-
         ;;
   00000015)  # Increase volume
-        amixer set Master 5%+
+        /sbin/minijail ${MINIJAIL_FLAGS} --uid=${USER_ID} -- \
+            /usr/bin/amixer set Master 5%+
         ;;
 esac