Add test coverage for CrasAudioHandler.

chromeos/chromeos.gyp

Index: chromeos/chromeos.gyp
diff --git a/chromeos/chromeos.gyp b/chromeos/chromeos.gyp
index 04459d66f98790b77bfa99ba577d023010b5f65f..417d3ac853a3023c2f817e6d162ad3e85bc38901 100644
--- a/chromeos/chromeos.gyp
+++ b/chromeos/chromeos.gyp
@@ -40,8 +40,8 @@
         'audio/audio_pref_handler.h',
         'audio/cras_audio_handler.cc',
         'audio/cras_audio_handler.h',
-        'audio/mock_cras_audio_handler.cc',
-        'audio/mock_cras_audio_handler.h',
+        'audio/audio_devices_pref_handler_stub.cc',
+        'audio/audio_devices_pref_handler_stub.h',
         'attestation/attestation_constants.cc',
         'attestation/attestation_constants.h',
         'attestation/attestation_flow.cc',
@@ -77,6 +77,8 @@
         'dbus/bluetooth_profile_service_provider.h',
         'dbus/cras_audio_client.cc',
         'dbus/cras_audio_client.h',
+        'dbus/cras_audio_client_stub_impl.cc',
+        'dbus/cras_audio_client_stub_impl.h',
         'dbus/cros_disks_client.cc',
         'dbus/cros_disks_client.h',
         'dbus/cryptohome_client.cc',
@@ -455,6 +457,7 @@
       'sources': [
         'app_mode/kiosk_oem_manifest_parser_unittest.cc',
         'attestation/attestation_flow_unittest.cc',
+        'audio/cras_audio_handler_unittest.cc',
         'dbus/blocking_method_caller_unittest.cc',
         'dbus/cros_disks_client_unittest.cc',
         'dbus/gsm_sms_client_unittest.cc',