Extends IBusObject to handle attachment field.

chromeos/dbus/ibus/ibus_lookup_table.h

Index: chromeos/dbus/ibus/ibus_lookup_table.h
diff --git a/chromeos/dbus/ibus/ibus_lookup_table.h b/chromeos/dbus/ibus/ibus_lookup_table.h
index 73d11bd79f28525cdff94ed70eae4d5abd062810..0e1fe0f2ecf79d1f24bc3c6f056a791b25bc15d5 100644
--- a/chromeos/dbus/ibus/ibus_lookup_table.h
+++ b/chromeos/dbus/ibus/ibus_lookup_table.h
@@ -126,7 +126,9 @@ class CHROMEOS_EXPORT IBusLookupTable {
   const std::vector<Entry>& candidates() const { return candidates_; }
   std::vector<Entry>* mutable_candidates() { return &candidates_; }
 
-  bool show_window_at_composition() { return show_window_at_composition_; }
+  bool show_window_at_composition() const {
+    return show_window_at_composition_;
+  }
   void set_show_window_at_composition(bool show_window_at_composition) {
     show_window_at_composition_ = show_window_at_composition;
   }