Move chromeos::GetInterfacesFromIntrospectResult into IntrospectableClient

chromeos/dbus/introspectable_client.h

Index: chromeos/dbus/introspectable_client.h
diff --git a/chromeos/dbus/introspectable_client.h b/chromeos/dbus/introspectable_client.h
index c21eb94c49dd840c7aa88c10cf12387f8906e8a3..c70bb6e1476b4a417dcd989251c885ff978be1a1 100644
--- a/chromeos/dbus/introspectable_client.h
+++ b/chromeos/dbus/introspectable_client.h
@@ -42,6 +42,12 @@ class CHROMEOS_EXPORT IntrospectableClient {
                           const dbus::ObjectPath& object_path,
                           const IntrospectCallback& callback) = 0;
 
+  // Parses XML-formatted introspection data returned by
+  // org.freedesktop.DBus.Introspectable.Introspect and returns the list of
+  // interface names declared within.
+  static std::vector<std::string> GetInterfacesFromIntrospectResult(
+      const std::string& xml_data);
+
   // Creates the instance
   static IntrospectableClient* Create(DBusClientImplementationType type,
                                       dbus::Bus* bus);