[IME] migrate the xkb ID to extension based xkb ID.

chromeos/ime/extension_ime_util.h

Index: chromeos/ime/extension_ime_util.h
diff --git a/chromeos/ime/extension_ime_util.h b/chromeos/ime/extension_ime_util.h
index bdcc896c631f321bd0bc72a315d2183e04c39c2d..13e0c6f110ffde20e7227192161d888a11ff7733 100644
--- a/chromeos/ime/extension_ime_util.h
+++ b/chromeos/ime/extension_ime_util.h
@@ -32,6 +32,10 @@ std::string CHROMEOS_EXPORT GetComponentInputMethodID(
 std::string CHROMEOS_EXPORT GetExtensionIDFromInputMethodID(
     const std::string& input_method_id);
 
+// Returns InputMethodID from keyboard layout (xkb) id (e.g. xkb:fr:fra).
+std::string CHROMEOS_EXPORT GetInputMethodIDByKeyboardLayout(
+    const std::string& keyboard_layout_id);
+
 // Returns true if |input_method_id| is extension IME ID. This function does not
 // check |input_method_id| is installed extension IME.
 bool CHROMEOS_EXPORT IsExtensionIME(const std::string& input_method_id);