use push messaging in cache invalidation xmpp channel

jingle/notifier/listener/push_notifications_send_update_task.cc

Index: jingle/notifier/listener/push_notifications_send_update_task.cc
===================================================================
--- jingle/notifier/listener/push_notifications_send_update_task.cc	(revision 119260)
+++ jingle/notifier/listener/push_notifications_send_update_task.cc	(working copy)
@@ -44,10 +44,12 @@
   const buzz::QName kQnPush(kPushNotificationsNamespace, "push");
   const buzz::QName kQnChannel(buzz::STR_EMPTY, "channel");
   const buzz::QName kQnData(kPushNotificationsNamespace, "data");
+  const buzz::QName kQnRecipient(kPushNotificationsNamespace, "recipient");
 
   // Create our update stanza. The message is constructed as:
   // <message from='{full jid}' to='{bare jid}' type='headline'>
   //   <push xmlns='google:push' channel='{channel}'>
+  //     [<recipient to='{bare jid}'>{base-64 encoded data}</data>]*
   //     <data>{base-64 encoded data}</data>
   //   </push>
   // </message>
@@ -60,6 +62,24 @@
   push->AddAttr(kQnChannel, notification.channel);
   message->AddElement(push);
 
+  const RecipientList& recipients = notification.recipients;
+  for (size_t i = 0; i < recipients.size(); ++i) {
+    const Recipient& recipient = recipients[i];
+    buzz::XmlElement* recipient_element =
+        new buzz::XmlElement(kQnRecipient, true);
+    push->AddElement(recipient_element);
+    recipient_element->AddAttr(buzz::QN_TO, recipient.to);
+    if (!recipient.user_specific_data.empty()) {
+      std::string base64_data;
+      if (!base::Base64Encode(recipient.user_specific_data, &base64_data)) {
+        LOG(WARNING) << "Could not encode data "
+                     << recipient.user_specific_data;
+      } else {
+        recipient_element->SetBodyText(base64_data);
+      }
+    }
+  }
+
   buzz::XmlElement* data = new buzz::XmlElement(kQnData, true);
   std::string base64_data;
   if (!base::Base64Encode(notification.data, &base64_data)) {