Support comma separated hardware keyboard layout.

chrome/browser/chromeos/preferences.cc

Index: chrome/browser/chromeos/preferences.cc
diff --git a/chrome/browser/chromeos/preferences.cc b/chrome/browser/chromeos/preferences.cc
index d25473dc5b53b82c45e00ea12c1eb0595ae07678..d8af970e69bc9b35b631faeb0349f5ed35bd8ca4 100644
--- a/chrome/browser/chromeos/preferences.cc
+++ b/chrome/browser/chromeos/preferences.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/chromeos/preferences.h"
 
+#include <vector>
+
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/magnifier/magnifier_constants.h"
 #include "ash/shell.h"
@@ -92,8 +94,9 @@ void Preferences::RegisterProfilePrefs(
     input_method::InputMethodManager* manager =
         input_method::InputMethodManager::Get();
     if (manager) {
-      hardware_keyboard_id =
-          manager->GetInputMethodUtil()->GetHardwareInputMethodId();
+      const std::vector<std::string>& hardware_layouts =
+          manager->GetInputMethodUtil()->GetHardwareInputMethodIds();
+      hardware_keyboard_id = JoinString(hardware_layouts, ',');
     }
   } else {
     hardware_keyboard_id = "xkb:us::eng";  // only for testing.