Implement the psychic search engine.

(a) Add a new subclass of SearchEngine that receives
suggestions provided by psychic and displays them in the
suggestions dropdown.
(b) Add a Labs setting that can turn this feature on or
off.

Change-Id: Icae05b6b55f489278028e5af560d9b36014a0f59
diff --git a/res/xml/lab_preferences.xml b/res/xml/lab_preferences.xml
index 16a5169..87383b0 100644
--- a/res/xml/lab_preferences.xml
+++ b/res/xml/lab_preferences.xml
@@ -29,4 +29,9 @@
         android:title="@string/pref_lab_most_visited_homepage"
         android:summary="@string/pref_lab_most_visited_homepage_summary" />
 
+    <CheckBoxPreference
+        android:key="use_instant_search"
+        android:defaultValue="false"
+        android:title="@string/pref_use_instant_search"
+        android:summary="@string/pref_use_instant_search_summary" />
 </PreferenceScreen>