[Sync] Make P2PNotifier behave more like InvalidationNotifier

chrome/browser/sync/notifier/p2p_notifier.h

Index: chrome/browser/sync/notifier/p2p_notifier.h
diff --git a/chrome/browser/sync/notifier/p2p_notifier.h b/chrome/browser/sync/notifier/p2p_notifier.h
index 0aa415da55a59226995d060e5733a7b3a049ccea..90ff99a59838414544f82d859d992098f6bc79a4 100644
--- a/chrome/browser/sync/notifier/p2p_notifier.h
+++ b/chrome/browser/sync/notifier/p2p_notifier.h
@@ -23,17 +23,66 @@ class MessageLoopProxy;
 }
 
 
-namespace notifier {
-struct NotifierOptions;
-}  // namespace
-
 namespace sync_notifier {
 
+// The intended recipient(s) of a P2P notification.
+enum P2PNotificationTarget {
+  NOTIFY_SELF,
+  FIRST_NOTIFICATION_TARGET = NOTIFY_SELF,
+  NOTIFY_OTHERS,
+  NOTIFY_ALL,
+  LAST_NOTIFICATION_TARGET = NOTIFY_ALL
+};
+
+std::string P2PNotificationTargetToString(
+    P2PNotificationTarget target);
+
+// If |target_str| can't be parsed, assumes NOTIFY_SELF.
+P2PNotificationTarget P2PNotificationTargetFromString(
+    const std::string& target_str);
+
+// Helper notification data class that can be serialized to and
+// deserialized from a string.
+class P2PNotificationData {
+ public:
+  // Initializes with an empty sender ID, target set to NOTIFY_SELF,
+  // and empty changed types.
+  P2PNotificationData();
+  P2PNotificationData(const std::string& sender_id,
+                      P2PNotificationTarget target,
+                      const syncable::ModelTypeSet& changed_types);
+
+  ~P2PNotificationData();
+
+  // Returns true if the given ID is targeted by this notification.
+  bool IsTargeted(const std::string& id) const;
+
+  const syncable::ModelTypeSet& GetChangedTypes() const;
+
+  bool Equals(const P2PNotificationData& other) const;
+
+  std::string ToString() const;
+
+  // Returns whether parsing |str| was successful.  If parsing was
+  // unsuccessful, the state of the notification is undefined.
+  bool ResetFromString(const std::string& str);
+
+ private:
+  // The unique ID of the client that sent the notification.
+  std::string sender_id_;
+  // The intendent recipient(s) of the notification.
+  P2PNotificationTarget target_;
+  // The types the notification is for.
+  syncable::ModelTypeSet changed_types_;
+};
+
 class P2PNotifier
     : public SyncNotifier,
       public notifier::TalkMediator::Delegate {
  public:
-  explicit P2PNotifier(const notifier::NotifierOptions& notifier_options);
+  // Takes ownership of |talk_mediator|, but it is guaranteed that
+  // |talk_mediator| is destroyed only when this object is destroyed.
+  explicit P2PNotifier(notifier::TalkMediator* talk_mediator);
 
   virtual ~P2PNotifier();
 
@@ -45,8 +94,9 @@ class P2PNotifier
   virtual void UpdateCredentials(
       const std::string& email, const std::string& token) OVERRIDE;
   virtual void UpdateEnabledTypes(
-      const syncable::ModelTypeSet& types) OVERRIDE;
-  virtual void SendNotification() OVERRIDE;
+      const syncable::ModelTypeSet& enabled_types) OVERRIDE;
+  virtual void SendNotification(
+      const syncable::ModelTypeSet& changed_types) OVERRIDE;
 
   // TalkMediator::Delegate implementation.
   virtual void OnNotificationStateChange(bool notifications_enabled);
@@ -54,15 +104,19 @@ class P2PNotifier
       const notifier::Notification& notification);
   virtual void OnOutgoingNotification();
 
+  // For testing.
+  void SendNotificationDataForTest(
+      const P2PNotificationData& notification_data);
+
  private:
-  // Call OnIncomingNotification() on observers if we have a non-empty
-  // set of enabled types.
-  void MaybeEmitNotification();
+  void SendNotificationData(const P2PNotificationData& notification_data);
 
   ObserverList<SyncNotifierObserver> observer_list_;
 
   // The actual notification listener.
   scoped_ptr<notifier::TalkMediator> talk_mediator_;
+  // Our unique ID.
+  std::string unique_id_;
   // Whether we called Login() on |talk_mediator_| yet.
   bool logged_in_;
   // Whether |talk_mediator_| has notified us that notifications are