Add bookmarks search activity to browser.

This activity is never started from the browser. Its purpose
is to provide bookmark suggestions to global search (through
its searchable meta-data), and to handle the intents produced
by clicking such suggestions.
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 98142ac..040cf45 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -38,6 +38,8 @@
     <string name="password">Password</string>
     <!-- The label on the "sign in" button -->
     <string name="action">Sign in</string>
+    <!-- The name of the bookmarks and history search suggestion source.  -->
+    <string name="bookmarks_search">Bookmarks &amp; history</string>
 
     <!-- Label for a cancel button.  It is used for multiple cancel buttons in different contexts -->
     <string name="cancel">Cancel</string>