Add annotations for RMS tests.

TEST=Run related test on LINK
BUG=None

Change-Id: I1fe4358b7dc58e497e0b8ebe015dc8993dd22811
Reviewed-on: https://chromium-review.googlesource.com/179763
Reviewed-by: Owen Lin <owenlin@chromium.org>
Commit-Queue: Owen Lin <owenlin@chromium.org>
Tested-by: Owen Lin <owenlin@chromium.org>
diff --git a/client/cros/audio/alsa_utils.py b/client/cros/audio/alsa_utils.py
index d169d3a..9281ca7 100644
--- a/client/cros/audio/alsa_utils.py
+++ b/client/cros/audio/alsa_utils.py
@@ -9,6 +9,7 @@
 
 ARECORD_PATH='/usr/bin/arecord'
 APLAY_PATH='/usr/bin/aplay'
+AMIXER_PATH='/usr/bin/amixer'
 
 def _get_format_args(channels, bits, rate):
     args = ['-c', str(channels)]
@@ -109,3 +110,9 @@
 
     # If there is only one soundcard, return it, else return not found (None)
     return 0 if id == 1 else None
+
+def dump_control_contents(device=None):
+    if device is None:
+        device = 'hw:%d' % get_default_soundcard_id()
+    args = [AMIXER_PATH, '-D', device, 'contents']
+    return cmd_utils.execute(args, stdout=subprocess.PIPE)