Revert of Remove disable-app-list-voice-search flag.

ui/app_list/app_list_switches.cc

Index: ui/app_list/app_list_switches.cc
diff --git a/ui/app_list/app_list_switches.cc b/ui/app_list/app_list_switches.cc
index d0c77d276fe08e0e0d88ee7bc49aa5639d5ee8cd..4e9ebf3059f96d55a969a117aff81925537fb343 100644
--- a/ui/app_list/app_list_switches.cc
+++ b/ui/app_list/app_list_switches.cc
@@ -14,6 +14,9 @@
 
 // Disables syncing of the app list independent of extensions.
 const char kDisableSyncAppList[] = "disable-sync-app-list";
+
+// If set, the voice search is disabled in app list UI.
+const char kDisableVoiceSearch[] = "disable-app-list-voice-search";
 
 // If set, the app list will be centered and wide instead of tall.
 const char kEnableCenteredAppList[] = "enable-centered-app-list";
@@ -48,7 +51,7 @@
 bool IsVoiceSearchEnabled() {
   // Speech recognition in AppList is only for ChromeOS right now.
 #if defined(OS_CHROMEOS)
-  return true;
+  return !CommandLine::ForCurrentProcess()->HasSwitch(kDisableVoiceSearch);
 #else
   return false;
 #endif