dbus: Stop accessing ObjectProxy::name_owner_changed_callback_ on the D-Bus thread

dbus/object_proxy.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DBUS_OBJECT_PROXY_H_
 #define DBUS_OBJECT_PROXY_H_
 
 #include <dbus/dbus.h>
 
 #include <map>
@@ skipping 54 matching lines @@
   // Called when an error response is returned or no response is returned.
   // Used for CallMethodWithErrorCallback().
   typedef base::Callback<void(ErrorResponse*)> ErrorCallback;
 
   // Called when the response is returned. Used for CallMethod().
   typedef base::Callback<void(Response*)> ResponseCallback;
 
   // Called when a signal is received. Signal* is the incoming signal.
   typedef base::Callback<void (Signal*)> SignalCallback;
 
+  // Called when NameOwnerChanged signal is received.
+  typedef base::Callback<void(
+      const std::string& old_owner,
+      const std::string& new_owner)> NameOwnerChangedCallback;
+
   // Called when the object proxy is connected to the signal.
   // Parameters:
   // - the interface name.
   // - the signal name.
   // - whether it was successful or not.
   typedef base::Callback<void (const std::string&, const std::string&, bool)>
       OnConnectedCallback;
 
   // Calls the method of the remote object and blocks until the response
   // is returned. Returns NULL on error.
@@ skipping 53 matching lines @@
   //
   // Must be called in the origin thread.
   virtual void ConnectToSignal(const std::string& interface_name,
                                const std::string& signal_name,
                                SignalCallback signal_callback,
                                OnConnectedCallback on_connected_callback);
 
   // Sets a callback for "NameOwnerChanged" signal. The callback is called on
   // the origin thread when D-Bus system sends "NameOwnerChanged" for the name
   // represented by |service_name_|.
-  virtual void SetNameOwnerChangedCallback(SignalCallback callback);
+  virtual void SetNameOwnerChangedCallback(NameOwnerChangedCallback callback);
 
   // Detaches from the remote object. The Bus object will take care of
   // detaching so you don't have to do this manually.
   //
   // BLOCKING CALL.
   virtual void Detach();
 
   // Returns an empty callback that does nothing. Can be used for
   // CallMethod().
   static ResponseCallback EmptyResponseCallback();
@@ skipping 87 matching lines @@
 
   // Calls D-Bus's GetNameOwner method synchronously to update
   // |service_name_owner_| with the current owner of |service_name_|.
   //
   // BLOCKING CALL.
   void UpdateNameOwnerAndBlock();
 
   // Handles NameOwnerChanged signal from D-Bus's special message bus.
   DBusHandlerResult HandleNameOwnerChanged(scoped_ptr<dbus::Signal> signal);
 
+  // Runs |name_owner_changed_callback_|.
+  void RunNameOwnerChangedCallback(const std::string& old_owner,
+                                   const std::string& new_owner);
+
   scoped_refptr<Bus> bus_;
   std::string service_name_;
   ObjectPath object_path_;
 
   // True if the message filter was added.
   bool filter_added_;
 
   // The method table where keys are absolute signal names (i.e. interface
   // name + signal name), and values are lists of the corresponding callbacks.
   typedef std::map<std::string, std::vector<SignalCallback> > MethodTable;
   MethodTable method_table_;
 
   // The callback called when NameOwnerChanged signal is received.
-  SignalCallback name_owner_changed_callback_;
+  NameOwnerChangedCallback name_owner_changed_callback_;
 
   std::set<std::string> match_rules_;
 
   const bool ignore_service_unknown_errors_;
 
   // Known name owner of the well-known bus name represnted by |service_name_|.
   std::string service_name_owner_;
 
   DISALLOW_COPY_AND_ASSIGN(ObjectProxy);
 };
 
 }  // namespace dbus
 
 #endif  // DBUS_OBJECT_PROXY_H_