search: make sure to pass a timestamp to LaunchSearch()

Do not repeat past mistakes while we're still in time.

https://bugzilla.gnome.org/show_bug.cgi?id=690009

data/org.gnome.ShellSearchProvider2.xml

@@ -75,11 +75,13 @@
     <!--
         LaunchSearch:
         @terms: Array of search terms, which the provider should treat as logical AND.
+        @timestamp: A timestamp of the user interaction that triggered this call
 
         Asks the search provider to launch a full search in the application for the provided terms.
     -->
     <method name="LaunchSearch">
       <arg type="as" name="terms" direction="in" />
+      <arg type="u" name="timestamp" direction="in" />
     </method>
   </interface>
 </node>

js/ui/remoteSearch.js

@@ -50,6 +50,7 @@ const SearchProvider2Iface = <interface name="org.gnome.Shell.SearchProvider2">
 </method>
 <method name="LaunchSearch">
     <arg type="as" direction="in" />
+    <arg type="u" direction="in" />
 </method>
 </interface>;
 
@@ -290,6 +291,6 @@ const RemoteSearchProvider2 = new Lang.Class({
     },
 
     launchSearch: function(terms) {
-        this.proxy.LaunchSearchRemote(terms);
+        this.proxy.LaunchSearchRemote(terms, global.get_current_time());
     }
 });