Do not try to get a display name from an input method ID which starts with "_ext_ime".

chrome/browser/chromeos/input_method/input_method_util.h

Index: chrome/browser/chromeos/input_method/input_method_util.h
diff --git a/chrome/browser/chromeos/input_method/input_method_util.h b/chrome/browser/chromeos/input_method/input_method_util.h
index f99bb084c4ca1f91a0f5710c3eee6c236b941b7e..22018fe26db182f94e72ff647115bf4c562d2ddc 100644
--- a/chrome/browser/chromeos/input_method/input_method_util.h
+++ b/chrome/browser/chromeos/input_method/input_method_util.h
@@ -131,6 +131,9 @@ class InputMethodUtil {
   // Returns true if the given input method id is for a keyboard layout.
   static bool IsKeyboardLayout(const std::string& input_method_id);
 
+  // Returns true if the given input method id is for an extension input method.
+  static bool IsExtensionInputMethod(const std::string& input_method_id);
+
   // Converts a language code to a language display name, using the
   // current application locale. MaybeRewriteLanguageName() is called
   // internally.