Shill: ShillServiceClient destroys ShillClientHelpers when they are not need.

chromeos/dbus/shill_client_helper.h

Index: chromeos/dbus/shill_client_helper.h
diff --git a/chromeos/dbus/shill_client_helper.h b/chromeos/dbus/shill_client_helper.h
index b8f769c4fcf76dc0aaeb848b6584b78c7c875d72..52631a9028a4fb03e19dc874d2ee5693f2cceeb5 100644
--- a/chromeos/dbus/shill_client_helper.h
+++ b/chromeos/dbus/shill_client_helper.h
@@ -66,13 +66,23 @@ class ShillClientHelper {
 
   virtual ~ShillClientHelper();
 
+  // Returns true if there is a PropertyChangedObserver registered.
+  bool IsObserved() const;
+
+  // Returns true if the are method calls waiting for a response. If this
+  // function is called from within the return callback return true only if
+  // there are *other* calls waiting for a response.
+  bool IsWaitingResponse() const;
+
   // Adds an |observer| of the PropertyChanged signal.
   void AddPropertyChangedObserver(ShillPropertyChangedObserver* observer);
 
   // Removes an |observer| of the PropertyChanged signal.
   void RemovePropertyChangedObserver(ShillPropertyChangedObserver* observer);
 
-  // Starts monitoring PropertyChanged signal.
+  // Starts monitoring PropertyChanged signal. If there aren't observers for the
+  // PropertyChanged signal, the actual monitoring will be delayed until the
+  // first observer is added.
   void MonitorPropertyChanged(const std::string& interface_name);
 
   // Calls a method without results.
@@ -125,6 +135,9 @@ class ShillClientHelper {
                                        const base::Value& value);
 
  private:
+  // Starts monitoring PropertyChanged signal.
+  void MonitorPropertyChangedInternal(const std::string& interface_name);
+
   // Handles the result of signal connection setup.
   void OnSignalConnected(const std::string& interface,
                          const std::string& signal,
@@ -180,6 +193,8 @@ class ShillClientHelper {
   PropertyChangedHandler property_changed_handler_;
   ObserverList<ShillPropertyChangedObserver, true /* check_empty */>
       observer_list_;
+  int in_progress_calls_;
+  std::vector<std::string> monitored_interfaces_;
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.