Switch Audio Preferences to per device.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 62c5bc7d2bd41e88a1e60abc8e585e1e1942ce32..b7fd550f59e7c33282a00a9a619dea17de506055 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -116,7 +116,9 @@
 #endif
 
 #if defined(OS_CHROMEOS)
+#include "ash/ash_switches.h"
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager.h"
+#include "chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h"
 #include "chrome/browser/chromeos/audio/audio_handler.h"
 #include "chrome/browser/chromeos/audio/audio_pref_handler_impl.h"
 #include "chrome/browser/chromeos/customization_document.h"
@@ -242,7 +244,11 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
 #endif
 
 #if defined(OS_CHROMEOS)
-  chromeos::AudioPrefHandlerImpl::RegisterPrefs(registry);
+  if (CommandLine::ForCurrentProcess()->

[Pam (message me for reviews), 2013/05/02 15:11:40]

I'm not too excited by this dependency on the command line. It would be cleaner
to pull the common pref registration for the old and new handlers out into
shared code, or alternatively to  have the new handler check to see if the
shared prefs have already been registered and register only its new ones if so.

[rkc, 2013/05/02 18:46:09]

Done.

+      HasSwitch(ash::switches::kAshDisableNewAudioHandler))
+    chromeos::AudioPrefHandlerImpl::RegisterPrefs(registry);
+  else
+    chromeos::AudioDevicesPrefHandlerImpl::RegisterPrefs(registry);
   chromeos::DataPromoNotification::RegisterPrefs(registry);
   chromeos::DeviceOAuth2TokenService::RegisterPrefs(registry);
   chromeos::device_settings_cache::RegisterPrefs(registry);