Add device policy: Kiosk Virtual Keyboard Layout.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 11d946d58c546949316bfc409193bda25218098f..28dbb731b03ddee9d1d8c23c814d75d5ec86319d 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -878,6 +878,10 @@ const char kCurrentWallpaperAppName[] = "wallpaper.app.name";
 // List of mounted file systems via the File System Provider API. Used to
 // restore them after a reboot.
 const char kFileSystemProviderMounted[] = "file_system_provider.mounted";
+
+// A boolean pref set to true if the virtual keyboard should be enabled.
+const char kTouchVirtualKeyboardEnabled[] = "ui.touch_virtual_keyboard_enabled";
+
 #endif  // defined(OS_CHROMEOS)
 
 // The disabled messages in IPC logging.