Move all white-listed input method indicator text from InputMethodUtil to manifests of IME extensio…

chromeos/ime/extension_ime_util.cc

Index: chromeos/ime/extension_ime_util.cc
diff --git a/chromeos/ime/extension_ime_util.cc b/chromeos/ime/extension_ime_util.cc
index ee37cae714aad5eef219585026d3c3bc34669582..bc0d078aaef24f1ccc378243b525aed56ec6cfc0 100644
--- a/chromeos/ime/extension_ime_util.cc
+++ b/chromeos/ime/extension_ime_util.cc
@@ -116,8 +116,10 @@ bool IsMemberOfExtension(const std::string& input_method_id,
 }
 
 bool IsKeyboardLayoutExtension(const std::string& input_method_id) {
-  std::string prefix = kComponentExtensionIMEPrefix;
-  return StartsWithASCII(input_method_id, prefix + kXkbExtensionId, true);
+  if (IsComponentExtensionIME(input_method_id))
+    return StartsWithASCII(GetComponentIDByInputMethodID(input_method_id),
+                           "xkb:", true);
+  return false;
 }
 
 std::string MaybeGetLegacyXkbId(const std::string& input_method_id) {