cros: Enable new cras audio handler by default

ash/test/ash_test_helper.cc

Index: ash/test/ash_test_helper.cc
diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index 172a7875b943ea473db9c8b4d67c66adbb604507..2f9481bd25934006c692fb9b16132dde3520dbc6 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -45,6 +45,10 @@ AshTestHelper::~AshTestHelper() {
 }
 
 void AshTestHelper::SetUp() {
+  // TODO(jennyz): Create mock or test AudioHandler so we can instantiate
+  // an ash::Shell with the new CrasAudioHandler. crbug.com/233266
+  CommandLine::ForCurrentProcess()->AppendSwitch(
+      ash::switches::kAshDisableNewAudioHandler);
   // TODO(jamescook): Can we do this without changing command line?
   // Use the origin (1,1) so that it doesn't over
   // lap with the native mouse cursor.